Moscow’s call for a joint UK/Russian investigation into the Salisbury poisoning has been dismissed as “perverse” by Britain’s delegation to the Organisation for the Prohibition of Chemical Weapons.

The move came as the OPCW’s executive council met in The Hague to discuss the attack on Sergei and Yulia Skripal at the request of Russia.

The Russian initiative was described by the Foreign Office as a “diversionary tactic” designed to undermine the OPCW’s work in analysing samples of the substance identified by the UK as a Novichok nerve agent.

Tension between Moscow and London has risen a notch after the head of the Porton Down military research facility said scientists had not verified Russia as the source of the substance.

Vladimir Putin seized on the comments from the chief executive of the Government’s Defence Science and Technology Laboratory (DSTL), Gary Aitkenhead, as he accused the UK of launching an “anti-Russian campaign”.

And Labour’s Diane Abbott suggested the Government had rushed to blame the Russian president.

Russia has flatly denied UK claims that it was to blame for the March 4 attack, with foreign intelligence service director Sergei Naryshkin even claiming it was staged by the UK and US as a “provocation”.

Mr Naryshkin told a global security conference in Moscow: “Even as far as the Skripal case goes – which is a grotesque provocation rudely staged by the British and US intelligence agencies – some European countries are in no hurry to follow London and Washington, preferring to sort the situation out.”

Moscow continues to demand that Britain hands over samples of the substance so it can carry out its own checks.

But the UK OPCW delegation said in a tweet: “Russia’s proposal for a joint UK/Russian investigation into the Salisbury incident is perverse. It is a diversionary tactic, and yet more disinformation designed to evade the questions the Russian authorities must answer.”

And a Foreign Office spokesman said there was “no requirement in the chemical weapons convention for the victim of a chemical weapons attack to engage in a joint investigation with the likely perpetrator”.

The spokesman described Wednesday’s meeting in The Hague as “yet another diversionary tactic, intended to undermine the work of the OPCW in reaching a conclusion”.

He said: “Russia has called this meeting to undermine the work of the OPCW which, fully in accordance with the chemical weapons convention, is providing the UK with technical assistance and evaluation through independent analysis of samples from the Salisbury attack.”

Mr Aitkenhead said on Tuesday that Porton Down had identified the substance used in Salisbury as a military-grade Novichok nerve agent which could probably be deployed only by a nation-state.

But he told Sky News it was not the role of his lab to work out where the agent came from and said the Government’s conclusion that it was highly likely to be Russian was based on “a number of other sources”.

His comments appeared to contradict the answer given by Foreign Secretary Boris Johnson when asked on German TV on March 20 why the UK believed the source of the nerve agent was Russia.

“The people from Porton Down, the laboratory, they were absolutely categorical,” Mr Johnson said. “I asked them that myself. I said ‘Are you sure?’ He said ‘There’s no doubt’.”

And on March 22, the Foreign Office issued a tweet saying: “Analysis by world-leading experts at the Defence Science and Technology Laboratory at Porton Down made clear that this was a military-grade Novichok nerve agent produced in Russia.”

Ms Abbott said the development raised questions about the Government’s approach, and said Labour leader Jeremy Corbyn should now be given credit for demanding more evidence before allocating blame.

“It doesn’t surprise me Porton Down is saying this because the security services were always very cautious in what they said,” the shadow home secretary told BBC Radio 4’s Today programme.

“What surprised me was that so many were willing to rush into the media and say it was unequivocally Putin. That’s not necessarily what we were told.”

Ms Abbott acknowledged that Prime Minister Theresa May had been “quite careful” in her language, but added: “Boris Johnson apparently going on international media and saying he was 101% certain it was Putin – I don’t understand where he got that information from.”

During a visit to Turkey, Mr Putin called for a thorough investigation into the poisoningy, saying “the speed at which the anti-Russian campaign has been launched causes bewilderment”.

Following Mr Aitkenhead’s comments, a Government spokesman said ministers had always been clear that the identification of the substance as Novichok by the Porton Down experts was “only one part of the intelligence picture” leading to the assessment that Russian state involvement was the only plausible explanation for the attack.

But Russia’s EU ambassador, Vladimir Chizhov, insisted that the nerve agent “could have been manufactured anywhere”.

Russian news agency Tass quoted Mr Chizhov as saying he was “not surprised” by Mr Aitkenhead’s comments, as Novichok “is widely known – its formula is even available on the internet”.</s>The Labour party is calling on Boris Johnson to answer some “very serious questions” after it emerged that scientists have not been able to identify the origin of the Novichok nerve agent.

The foreign secretary previously claimed in an interview to German TV station, Deutsche Welle, that he had been told in “categorical” terms by Porton Down scientists that there was “no doubt” Russia was the source of the nerve agent used in the Salisbury poisoning of the Skripals.

READ MORE: Did Boris Johnson lie that lab told him Russia was source of Salisbury nerve agent? (WATCH VIDEO)

Opposition leader Jeremy Corbyn says Johnson now needs to answer some questions. “Where does that leave the Foreign Secretary? Egg on his face for the statement he made on German television.”

“Boris Johnson seems to have completely exceeded the information that he had been given and told the world in categorical terms what he believed had happened and its not backed up by the evidence he claimed to have got from Porton Down in the first place. Boris Johnson needs to answer some questions,” Corbyn told Sky News.

Corbyn also criticized the Foreign Office for issuing a tweet reiterating Johnson’s statement following the interview and then deleting it, Tuesday, following the announcement from Porton Down. Shadow home secretary, Diane Abbott also highlighted the decision by the Foreign Office to delete the tweet.

Meanwhile the Foreign Office is standing by its assessment that Russia is responsible for the attack. In a tweet Tuesday it said “it is not and has never been our responsibility to confirm the source of the agent.”

Abbott accused the Foreign Office of misleading the public about the Porton Down novichok evidence in a statement. “It seems Boris Johnson misled the public when he claimed that Porton Down officials confirmed to him that Russia was the source of the nerve agent used in the Salisbury attack.

Those officials have made it clear they cannot identify its source, and are not able to definitively say it came from Russia or elsewhere.”

Abbot added that Johnson’s actions once again show he is unable to responsibly represent Britain on the world stage.

Shadow education secretary, Angela Rayner also called on Johnson to answer “some very serious questions,” adding “the usual bluff bluster” will not do.

Corbyn was attacked by the Tories and some of his own MPs for his apparent ‘weak’ response to alleged Russian aggression. Several Labour MPs condemned Corbyn’s position and accepted Theresa May’s assessment of Russian culpability.

The Labour leader took a more cautious approach to the Skripal poisoning calling for the utilisation of proper channels of international law before attributing blame.</s>Image copyright Reuters

Labour has called for an investigation into whether Boris Johnson "misled" the public over Russian involvement in the Salisbury nerve agent attack.

Labour leader Jeremy Corbyn earlier implied the foreign secretary had exaggerated the findings of the UK's defence laboratory, Porton Down.

Mr Johnson responded that Mr Corbyn's remarks were "lamentable".

Meanwhile, the international chemical weapons body has rejected Russian calls for a joint inquiry into the case.

Former Russian double-agent Sergei Skripal and his daughter Yulia remain in hospital after being poisoned by a nerve agent on 4 March.

The incident has caused a major diplomatic fallout, with the expulsion of some 150 Russian diplomats by the UK and its allies being met by counter-expulsions by Moscow.

Labour said in an interview given to German TV last month, Mr Johnson said that "people from Porton Down" were "absolutely categorical", adding: "I asked the guy myself. I said 'are you sure?', and he said 'there's no doubt'."

But on Tuesday the Porton Down laboratory said it could not verify the precise source of the Novichok nerve agent used, although it did say it was likely to have been deployed by a "state actor".

Labour called on the prime minister to launch an investigation into whether Mr Johnson broke the ministerial code.

'Egg on his face'

Shadow Cabinet Office minister, Jon Trickett, said Mr Johnson had "serious questions to answer".

"He clearly previously indicated that Porton Down had told him 'categorically' that Russia was the source of the nerve agent," he said.

Mr Corbyn said the foreign secretary had "egg on his face for the statement he made on German television".

"Either the foreign secretary has information that he's not sharing with Porton Down or it was a bit of exaggeration," he added.

Mr Johnson hit back on Twitter.

"It is lamentable that Jeremy Corbyn is now playing Russia's game and trying to discredit the UK over Salisbury attack," he wrote, setting out what he said were the "key facts".

He added: "28 other countries have been so convinced by UK case they have expelled Russians. In contrast, Jeremy Corbyn chooses to side with the Russian spin machine."

The UK has said that identifying the substance at Porton Down was "only one part of the intelligence picture".

It comes as Russia has also sought to discredit the UK's accusations.

Russia pointed to a now-deleted tweet by the Foreign Office which suggested Porton Down had "made clear" the nerve agent was "produced in Russia".

It had sought a joint inquiry after the UK blamed it for being the source of the Novichok nerve agent used.

Russia accused the UK of blocking access to an investigation being carried out by the Organization for the Prohibition of Chemical Weapons.

But it lost by 15 votes to six, while 17 member states abstained.

Following the verdict, Mr Johnson said Russia had failed in its attempts to "obscure the truth" and "derail the proper international process".

Image copyright EPA/ Yulia Skripal/Facebook Image caption Sergei Skripal, 66, and his daughter Yulia, 33, were poisoned by a nerve agent called Novichok

Russia has said the comments from Porton Down's chief executive Gary Aitkenhead reveal the UK's case to be "nothing but assumptions".

The Foreign Office said the deleted tweet had been part of a real-time account of a speech by the UK's ambassador in Moscow and was deleted because it "did not accurately report our ambassador's words".

It added: "None of this changes the fact that it is our assessment that Russia was responsible for this brazen and reckless act and, as the international community agrees, there is no other plausible explanation.

"No other country has a combination of the capability, the intent, and the motive to carry out such an act."

BBC diplomatic correspondent James Landale said Mr Johnson's "loose language" plus the deleted tweet represented a "self-inflicted wound" by the UK.

This had "muddied the waters" and allowed Russia to cast doubt on the UK's assessment, he said - but he added that the "international alliance" supporting the UK's position was "still holding".</s>Boris Johnson under pressure to explain whether position has changed after tweet blaming Moscow is deleted

This article is more than 1 year old

This article is more than 1 year old

Boris Johnson is facing embarrassing questions over his claims that Russia had produced the Salisbury nerve agent after it emerged that the Foreign Office had deleted a tweet blaming Moscow for the attack.



Once again, Boris Johnson is a liability to Britain. Why is he still in the job? | Ellie Mae O’Hagan Read more

With the foreign secretary already under pressure over his remarks two weeks ago that a Porton Down scientist had been “absolutely categorical” that the novichok had originated in the country, Jeremy Corbyn accused Johnson of “completely exceeding the information he had been given” after the emergence of the deleted tweet.

Play Video 0:32 Jeremy Corbyn questions Boris Johnson's claim on Russian-made novichok – video

But Johnson later hit back, accusing the Labour leader of “playing Russia’s game”.

The deletion, immediately seized on by the Russian embassy, has deepened the government’s difficulties after British scientists at the UK’s defence research laboratory announced on Tuesday that they had not established that the nerve agent used to poison Sergei and Yulia Skripal had been made in Russia.

After Porton Down said it had “not identified the precise source” of the poison, the Foreign Office issued a swift rebuttal saying the prime minister had always been clear that the assessment was “only one part” of the intelligence picture.

Play Video 0:26 'Absolutely categorical': Boris Johnson insists novichok was made in Russia – video

The announcement prompted claims from the Kremlin that Britain was lying about the origins of the novichok and demanded an apology from Theresa May.

However, it emerged on Wednesday that the Foreign Office had earlier deleted a tweet claiming the British scientists had concluded that the nerve agent was “produced in Russia”.

In an awkward development for the Foreign Office, the Russian embassy’s Twitter feed pointed out that the 20 March tweet on a presentation by Britain’s ambassador to Moscow on the Salisbury attack had disappeared.

Russian Embassy, UK (@RussianEmbassy) Why would @foreignoffice delete this tweet from 22 March? pic.twitter.com/Nvu1BfJw9J

The deleted tweet read: “Analysis by world-leading experts at the Defence Science and Technology laboratory at Porton Down made clear that this was a military grade nerve agent produced in Russia.”

Johnson is now under growing pressure to explain whether the government has shifted its position.

Timeline Boris Johnson's diplomatic gaffes as foreign secretary Show Hide Johnson has caused a string of diplomatic incidents with his words and actions Footage emerges of Johnson reciting inappropriate poem in Myanmar Visiting the Shwedagon Pagoda, the most sacred Buddhist site in Myanmar's former capital Yangon, Johnson starts reciting Rudyard Kipling's colonial-era poem The Road to Mandalay. UK ambassador Andrew Patrick steps in and stops him. The poem includes a reference to the Buddha as a “Bloomin’ idol made o’ mud/ Wot they called the Great Gawd Budd” Johnson refers to clearing away 'dead bodies' in Sirte At a Conservative conference fringe event Johnson draws gasps saying: “There’s a group of UK business people who want to invest in Sirte, on the coast, near where Gaddafi was captured and executed. They literally have a brilliant vision to turn Sirte into the next Dubai. The only thing they’ve got to do is clear the dead bodies away." Tory colleague Heidi Allen says the remarks are "100% unacceptable from anyone, let alone the foreign secretary”. A senior Downing Street source says: “We did not feel it was an appropriate choice of words.” Johnson disputes Nazanin Zaghari-Ratcliffe's reason for visiting Iran "When I look at what Zaghari-Ratcliffe was doing, she was simply teaching people journalism, as I understand it" the foreign secretary tells the foreign affairs committee. He is later forced to apologise in parliament, accepting that the British government believes, as Zaghari-Ratcliffe and her family assert, that the sole purpose of her visit to Iran was for a holiday. Despite a subsequent visit to Tehran by Johnson, Zaghari-Ratcliffe remains in prison, serving a five-year sentence. Compares Irish border Brexit question to London congestion charge While applying pressure over Brexit arrangements, a leaked document reveals Johnson had suggested the government’s task is not to maintain “no border” in Ireland, but to prevent it from “becoming significantly harder”. On the radio he goes on to say "There’s no border between Islington, Camden and Westminster, but when I was mayor of London we anaesthetically and invisibly took hundreds of millions of pounds from people travelling between those boroughs without any need for border checks.” Claims Porton Down informed him novichok source was Russia In an interview with Deutsche Welle's Zhanna Nemtsova, Johnson categorically asserts Porton Down informed him the nerve agent came from Russia. Nemtsova: You argue the source of this nerve agent, novichok, is Russia. How did you manage to find it out so quickly? Does Britain possess samples? Johnson: Let me be clear with you … When I look at the evidence, I mean the people from Porton Down, the laboratory … Nemtsova: So they have samples …? Johnson: They do. And they were absolutely categorical and I asked the guy myself, I said, "Are you sure?" and he said there's no doubt.



The security minister, Ben Wallace, said the Porton Down scientists had only provided one part of the picture and had never been expected to attribute responsibility for the attack.

He told the BBC: “Scientists are scientists. I, as well as national security, have organised crime [and] terrorism under my portfolio, and when we work with forensic scientists, the scientists tell us what something is. They tell me a gun and a type of gun was used, but the attribution of who used it, exactly how it was used, is a matter for the broader investigation.



“That includes intelligence, detectives if it’s a police investigation, and the scientists as well, and that’s perfectly understandable.”

Wallace, a close ally of the foreign secretary, defended Johnson for suggesting he had received assurances from government scientists that the nerve agent was categorically made in Russia.

“Porton Down will be able to tell you there are very, very, very few people in the world who, first of all, did design novichok – and that was the Russians – and who have developed and stockpiled it. In fact, the task of that is reduced to one,” he said.

A Foreign Office spokesman said: “An HMA Moscow [British ambassador Laurie Bristow] briefing on 22 March was tweeted in real time by @UKinRussia and amplified by @foreignoffice to explain what happened in Salisbury to as wide an audience as possible.



“One of the tweets was truncated and did not accurately report our ambassador’s words. We have removed this tweet.”

According to an official transcript of the speech, Bristow’s original words were: “The analysts at Porton Down, the Defence Science and Technology Laboratory in the UK, established and made clear that this was a military-grade chemical weapon. One of the novichok series; a nerve agent as I said produced in Russia.”

Corbyn, who faced criticism for his initial, cautious response to the novichok allegations, accused Johnson of exaggerating the evidence that Russia was to blame for the Salisbury poisoning.

Quick guide What is novichok? Show Hide Novichok refers to a group of nerve agents developed by the Soviet Union in the 1970s and 80s to elude international restrictions on chemical weapons. Like other nerve agents, they are organophosphate compounds, but the chemicals used to make them, and their final structures, are considered classified in the UK, the US and other countries. The most potent of the novichok substances are considered to be more lethal than VX, the most deadly of the familiar nerve agents, which include sarin, tabun and soman. While the novichok agents work in a similar way, by massively over-stimulating muscles and glands, one chemical weapons expert said the agents did not degrade fast in the environment and had 'an additional toxicity that was not well understood. Treatment for novichok exposure would be the same as for other nerve agents, namely with atropine, diazepam and potentially drugs called oximes. The chemical structures of novichok agents were made public in 2008 by Vil Mirzayanov, a former Russian scientist living in the US, but the structures have never been publicly confirmed. It is thought they can be made in different forms, including as a dust aerosol. The novichoks are known as binary agents because they only become lethal after mixing two otherwise harmless components. According to Mirzayanov, they are 10 to 100 times more toxic than conventional nerve agents. While laboratories that are used to police chemical weapons incidents have databases of nerve agents, few outside Russia are believed to have full details of the novichok compounds and the chemicals needed to make them. Photograph: Matt Cardy/Getty Images Europe

The Labour leader, asked on a campaign visit to Watford about the foreign secretary’s remarks, said: “He claimed categorically – and I think he used the words 101% – that it had come from Russia.

“Boris Johnson seems to have completely exceeded the information that he had been given and told the world in categorical terms what he believed had happened. And it’s not backed up by the evidence he claimed to have got from Porton Down in the first place. Boris Johnson needs to answer some questions.

He added that Johnson had been left with “egg on his face” over his interview.

In a series of tweets on Wednesday afternoon, Johnson dismissed Corbyn’s response, writing: “It is lamentable that Jeremy Corbyn is now playing Russia’s game and trying to discredit the UK over Salisbury attack... 28 other countries have been so convinced by UK case they have expelled Russians. In contrast, Jeremy Corbyn chooses to side with the Russian spin machine.”

The European commission said it had never thought that Porton Down had been tasked with identifying the source of the substance used in Salisbury.

The commission spokesman Alexander Winterstein told a Brussels press briefing: “Our understanding is that the role of the experts there was to identify the type of agent that was used, not the source of the agent ... They did identify the nerve agent novichok. That is what they have done.”</s>Boris Johnson is facing embarrassment over his claims about the Salisbury poisoning attack after the Foreign Office deleted a tweet claiming Russia had produced the nerve agent. The Foreign Secretary was under pressure to explain the change as the Russian Embassy in London ridiculed Britain’s stance linking Moscow to the attempted murder of former double agent Sergei Skripal and his daughter Yulia. Jeremy Corbyn said that Johnson had been “left with egg on his face” and had some “serious questions to answer”. Ministers were already on the defensive after the head of the Porton Down defence laboratory revealed on Tuesday that it had “not identified the precise source” of the poison. But in a further blow, it emerged that the FCO had deleted a tweet claiming that the UK’s leading defence scientists had indeed concluded that the nerve agent was “produced in Russia”. HuffPost has found a cached version of the deleted tweet.

Contrary to the FCO tweet, the ambassador had not stated that Porton Down had itself “made clear” that the Salisbury poison had been “produced in Russia”. A Foreign Office spokesman confirmed that the message had indeed been deleted, stating that it had not been an accurate reflection of the account given by Bristow. “An HMA [Her Majesty’s Ambassador] Moscow briefing on 22 March was tweeted in real time by @UKinRussia and amplied by @foreignoffice, to explain what happened in Salisbury to as wide an audience as possible,” the spokesman said. “One of the tweets was truncated and did not accurately report our Ambassador’s words. We have removed this tweet.” Foreign Office sources confirmed that the tweet had been removed on Wednesday. The FCO also put out a full transcript of the ambassador’s remarks in his briefing on the Salisbury attack.

The row had been sparked on Tuesday after Gary Aitkenhead, the chief executive of the Defence Science and Technology Laboratory at the facility, told Sky News on Tuesday that the lab had not identified the nerve agent as made in Russia. Shadow Home Secretary Diane Abbott suggested that Aitkenhead also cast doubt on Boris Johnson’s claim that Vladimir Putin was ‘unequivocally’ to blame for the attempted murder of a former Russian spy and his daughter. “It seems Boris Johnson misled the public when he claimed that Porton Down officials confirmed to him that Russia was the source of the nerve agent used in the Salisbury attack,” she said in a statement. “Those officials have made it clear they cannot identify its source, and are not able to definitively say it came from Russia or elsewhere. “Boris Johnson is supposed to represent Britain on the world stage, but time and again he has shown he is unable to do so responsibly.” Critics seized on the contrast between the scientists’ caution and the Foreign Secretary’s interview with a German news channel in which he declared British defence experts had told him that the Kremlin was behind the attack on Sergei and Yulia Skripal. Asked directly how he could assert that the source of the Novichok nerve agent was Russia, the Foreign Secretary replied that he had ‘interrogated’ the scientists. He then told DW.com: “People from Porton Down, they were absolutely categorical. I asked the guy myself I said ‘are you sure?’ and he said there’s no doubt.”

A Foreign Office spokesman told HuffPost suggested he was only referring to the fact that the agent was a ‘Novichok’ not that it was made in Russia. “The Foreign Secretary was making clear that Porton Down were sure it was a Novichok – a point they have reinforced. “He goes on in the same interview to make clear why based on that information, additional intelligence and the lack of alternative explanation from the Russians, we have reached the conclusion we have. “What the Foreign Secretary said then, and what Porton Down have said recently, is fully consistent with what we have said throughout. It is Russia that is putting forward multiple versions of events and obfuscating the truth.” Jeremy Corbyn faced criticism from Tories and some of his own MPs last month when he asked for more evidence to show Putin had ordered the attack, and refused to rule out the possibility that Moscow had lost control of the material. Abbott told BBC Radio 4’s Today programme that Corbyn had been vindicated for his stance, while Johnson’s own approach begged new questions. “I can’t speak in detail about the briefing. It doesn’t surprise me that Porton Down are saying this because the security services were always very cautious in what they said,” she said. “What surprised me was that so many people were willing to rush onto the media and say it was unequivocally Putin. That’s not necessarily what we were told.” “Boris Johnson going on international media and saying he was 101% certain it was Putin. I don’t understand where he got that information from. “We will I hope get some credit for taking a more thoughtful approach and asking the right questions.” Although Aitkenhead stressed that the nerve agent’s production was “something only in the capabilities of a state actor [ie a Government]”, Downing Street was forced to point out on Tuesday that Porton Down provided “only one part of the intelligence picture” that pointed to Moscow’s responsibility. The defence lab was forced to tweet a clarification too.

But Russia pounced on Aitkenhead’s remarks. Vladimir Putin’s spokesman, Dmitry Peskov, said Britain would have to apologise to Russia for its “mad accusations”. The Russian embassy in London said the UK’s claims that Moscow was behind the attack was a “bluff”. Hamish de Bretton-Gordon, a chemical weapons expert and former commander of the British Army’s Joint Chemical, Biological, Radiological and Nuclear Regiment, urged the Government to counter Russian ‘disinformation’ by producing its own evidence as to why Moscow was to blame. “Security organisations are always very circumspect about giving the evidence because it can betray a source,” he told the Today programme. “What is clear now is that somebody in the government, whether it is the Foreign Secretary or the Prime Minister, needs to lay out exactly what the supporting evidence is, that is compelling, that doesn’t betray sources.</s>The minister president of Germany's most populous state has lambasted the UK for prematurely pinning the blame for the Skripal poisoning case on Russia, writing thatArmin Laschet, the leader of North Rhine-Westphalia and a deputy chairman of Angela Merkel's Christian Democratic Union (CDU), took to Twitter after the UK's Porton Down government laboratory announced on Tuesday that it could not link nerve agent samples it had collected to Russia.Laschet said. "You can think of Russia what you want, but I have learned a different way of dealing with states from studying international law."UK Foreign Secretary Boris Johnson previously said that scientists at Porton Down were "categorical" about the Russian origin of the nerve agent allegedly used in the March 4 attack against Sergei Skripal, a former double agent, and his daughter in Salisbury. As part of a coordinated show of solidarity with the UK over the attack, Germany announced last month that it would expel four Russian diplomats over Moscow's suspected involvement in the poisoning."It is clear that there must be consequences. We in the European Union have therefore adopted an unequivocal position and stand shoulder-to-shoulder with the United Kingdom," German Foreign Minister Heiko Maas said in a statement announcing the expulsions.In total, more than 100 Russian diplomats were ordered to leave the European Union and NATO states at the UK's urging. Russia has denied any involvement in the Skripal poisoning, while also calling on the UK for a joint investigation.Moscow has also sent a list of 14 questions to the UK Foreign Office regarding the case, but still awaits a response. Another list with questions was sent to the Organization for the Prohibition of Chemical Weapons (OPCW), but Russia's representative to the body said it has received only one answer so far, which is being evaluated.</s>Boris Johnson has accused Jeremy Corbyn of "playing Russia's game" for challenging him over an interview on the Salisbury poisoning.

The Foreign Secretary said it was "lamentable" he was called upon to answer "serious questions" for appearing to suggest scientists at Porton Down were in "no doubt" the nerve agent came from Russia.</s>The head of Porton Down appears to have contradicted claims by Boris Johnson about the poisoning of a former spy, Sergei Skripal.

In an interview, the foreign secretary secretary talked about the scientific analysis of the Novichok nerve agent that was used. And he seemingly confirmed that the Porton Down defence research laboratory had “no doubt” that the substance was made in Russia.

However, Porton Down’s chief executive has now said that scientists have “not identified the precise source”.

You can read FactCheck’s long read about the case here.

Mr Johnson’s claims were made to German TV channel Deutsche Welle, while reiterating the British government’s allegations against Russia.

The interviewer asked him: “You argue that the source of this nerve agent, Novichok, is Russia. How did you manage to find it out so quickly? Does Britain possess samples of it?”

During the course of a long response, Mr Johnson appeared to suggest that scientists from the UK’s military laboratory were adamant that the Novichok was Russian-made.

He said: “I genuinely think Russia is an incredible country, a fantastic place, and it pains me to see the way things have got between us. So, I’m genuinely distressed by what has happened. But when I look at the evidence; I mean, the people from Porton Down, the laboratory…”

“They have the samples?” the interviewer interjected.

“They do,” replied Mr Johnson. “They do. And they were absolutely categorical and I asked the guy myself, I said, ‘Are you sure?’ And he said there’s no doubt.”

Mr Johnson’s comments do not appear to match with further remarks by the head of Porton Down himself.

Speaking yesterday, Gary Aitkenhead said: “We were able to identify it as Novichok, to identify that it was military-grade nerve agent.”

But he added: “We have not identified the precise source, but we have provided the scientific info to government who have then used a number of other sources to piece together the conclusions you have come to.”

Aitkenhead said that identifying the source would require “other inputs”, explaining: “It is our job to provide the scientific evidence of what this particular nerve agent is, we identified that it is from this particular family and that it is a military grade, but it is not our job to say where it was manufactured.”

The apparent contradiction has already been leapt on by Labour. Shadow home secretary, Diane Abbott, said: “I don’t understand where he got that information from.”

And Labour MP Chris Williamson said: “Boris Johnson is your Foreign Secretary and he just lied to justify our country’s foreign policy.”

Meanwhile, Sky News quotes an unnamed source in the Foreign Office who said Mr Johnson “misspoke”.

But this is not the only time the government has made this claim. The Russian embassy in London has highlighted a tweet by the Foreign Office last month. The tweet said that Porton Down had “made clear” that the Novichok nerve agent was “produced in Russia”.

The tweet has now been deleted, with the Foreign Office explaining that it had been “truncated and did not accurately report our Ambassador’s words”.

In a statement today, the Foreign Office backed Mr Johnson’s remarks by suggesting he had simply been referring to the identification of the nerve agent itself – rather than its source.

A spokesperson told FactCheck today: “The Foreign Secretary was making clear that Porton Down were sure it was a Novichok – a point they have reinforced. He goes on in the same interview to make clear why based on that information, additional intelligence and the lack of alternative explanation from the Russians, we have reached the conclusion we have.

“What the Foreign Secretary said then, and what Porton Down have said recently, is fully consistent with what we have said throughout. It is Russia that is putting forward multiple versions of events and obfuscating the truth.”

The Foreign Office had previously explained: “This is only one part of the intelligence picture. As the Prime Minister has set out in a number of statements to the Commons since 12 March, this includes our knowledge that within the last decade, Russia has investigated ways of delivering nerve agents probably for assassination – and as part of this programme has produced and stockpiled small quantities of Novichoks; Russia’s record of conducting state-sponsored assassinations; and our assessment that Russia views former intelligence officers as targets.”

What should we read into it all?

Gary Aitkenhead’s comment may be seen as undermining the government’s allegations against Russia.

However, it is worth noting that the government has always maintained that it’s case is multi-faceted. Chemistry is only part of the story.

Professor Alastair Hay told us: “My reading is that Gary Aitkenhead was simply reaffirming what Porton had said previously about the identity of the agent. He was making sure that the laboratory’s role is clear. He pointed out the UK Government was using other intelligence evidence it had to point the finger of blame at Russia.

“But I think it is good that Aitkenhead did the reaffirmation. It keeps Porton above the fray and recognised for its scientific ability.

“Unless Porton had had a prior sample from the facility where the Novichok was made it would have been difficult to identify the source. If the environmental samples had had other ingredients from the production process in them this could have helped identify how it was made and thus help to narrow down facilities. But in the absence of that prior sample pointing a finger would be unsound.”

Professor Andrea Sella told FactCheck: “This is only partly about the chemistry… It strikes me that the Russian government is doing everything it can to cast doubt on everything. They’ve repeatedly undermined Porton Down, for example by suggesting that it might have actually made and delivered the agent. Now they leap on this statement which is very clear and very simple – the chemistry is Novichok; there is additional information from other sources that corroborates the idea that the stuff came from Russia. The demands from the Russians that the UK share its information are a transparent attempt to get the UK to reveal its intelligence information.”

“Let’s face it, there is no plausible alternative scenario. It’s about the wider pattern – over and over inconvenient Russians have been bumped off, in the UK and elsewhere. Their behaviour fits with a long standing bait and switch pattern to confuse and obfuscate.”

We have no way of verifying what Porton Down scientists may have told Boris Johnson behind closed doors; nor do we know what he was intending to refer to in his comments.

However, the question put by the interviewer specifically referred to Russia – as did Mr Johnson’s preceding comments.

Therefore, we think people might reasonably have assumed he was claiming that Porton Down had scientific evidence to show the Novichok was made in Russia – a claim that has proved to be wrong.

At best, this means his comments were sloppy and ham-fisted. At worst, they were wrong and misleading.

The statements from Porton Down do not necessarily change the government’s overall evidence base particularly. After all, we knew all along that chemistry was only part of the story.

The statements reaffirm the importance of strong intelligence. But, as of yet, the government has not elaborated on what intelligence it has – or released any of it.</s>Mr Johnson made the comments after the chief executive of the Porton Down military facility admitted there was no proof linking the Novichok nerve agent used in the March 4 attack on Sergei and Yulia Skripal to Russia. Asked why the UK believed that Russia was the source of the nerve agent, Mr Johnson said: "The people from Porton Down, the laboratory, they were absolutely categorical. I asked them that myself. I said 'Are you sure?'. He said 'There's no doubt'."

Commenting on Mr Johnson's interview, a Government spokesman said: "The Foreign Secretary was making clear that Porton Down were sure it was a Novichok - a point they have reinforced. "He goes on in the same interview to make clear why based on that information, additional intelligence and the lack of alternative explanation from the Russians, we have reached the conclusion we have. "What the Foreign Secretary said then, and what Porton Down have said recently, is fully consistent with what we have said throughout. It is Russia that is putting forward multiple versions of events and obfuscating the truth." The Foreign Office also deleted a tweet insisting the novichok used in the Salisbury attack was definitely "produced in Russia". The tweet on March 22, said: "Analysis by world-leading experts at the Defence Science and Technology Laboratory at Porton Down made clear that this was a military-grade novichok nerve agent produced in Russia."

Labour leader Jeremy Corbyn has accused Mr Johnson of "exaggeration" over the evidence that Russia was to blame for the Salisbury poisoning. Speaking during a local election campaign visit to Watford, Mr Corbyn said: "He claimed categorically - and I think he used the words 101% - that it had come from Russia. Porton Down have not said that, they said that they've identified it as Novichok, they cannot identify the source of it. "Either the Foreign Secretary has information that he's not sharing with Porton Down or it was a bit of exaggeration. I don't know which it is, but I think we need a responsible, cool approach to this.

"We need to get to the source of this to prevent it ever happening again." Shadow home secretary Diane Abbott challenged the Foreign Secretary to explain his earlier comments. She said: ”It seems Boris Johnson misled the public when he claimed that Porton Down officials confirmed to him that Russia was the source of the nerve agent used in the Salisbury attack.

"Those officials have made it clear they cannot identify its source, and are not able to definitively say it came from Russia or elsewhere. "Boris Johnson is supposed to represent Britain on the world stage, but time and again he has shown he is unable to do so responsibly." Explaining the deletion of the tweet, a Foreign Office spokesman said it had been an inaccurate summary of comments made by the UK's ambassador to Russia, Laurie Bristow, at a briefing in Moscow. Referring to Dr Bristow as "HMA" - Her Majesty's Ambassador - the spokesman said: "A full transcript and video of the briefing have been available on GOV.UK since 22 March. "An HMA Moscow briefing on 22 March was tweeted in real time by @UKinRussia and amplified by @foreignoffice, to explain what happened in Salisbury to as wide an audience as possible. One of the tweets was truncated and did not accurately report our ambassador's words. We have removed this tweet."</s>Gary Aitkenhead, chief executive of the Defesce Science and Technology Laboratory at Porton Down in England, told Sky News that while the scientists managed to identify the chemical used in the Skripal poisoning case as a "military-grade nerve agent," they were unable to determine its "precise source."

About two weeks earlier, however, British Foreign Secretary Boris Johnson insisted during an interview with Deutsche Welle that Porton Down scientists were "absolutely categorical: when they allegedly assured him that "there’s no doubt" that the chemical came from Russia.

READ MORE: 'Embarrassing': Social Media Abuzz Over Russia Not Identified as Novichok Source

Many social media users were nonplussed by this development, voicing their concerns via Twitter and calling on Johnson to be held accountable.

​Some also complained about the BBC apparently being reluctant to report on this issue.

Dear BBC

Given the wall-to-wall coverage you relayed of the Skripal poisonings, the jingoism of May and Johnson and the attempts to humiliate Jeremy Corbyn, do you not think it is in the public interest to inform them of the latest developments at Porton Down? @BBCNews — Twenty8Sixty8 (@WilliamPMack) 4 апреля 2018 г.

​And others simply cracked jokes and quipped about Johnson’s predicament.
Jeremy Corbyn, leader of the opposition Labour Party, calls for an investigation into comments by UK Foreign Secretary Boris Johnson. Johnson is facing criticisms he overstated the strength of evidence against Russia, an accusation he calls "lamentable" and accuses Corbyn of sympathizing with Russia.