UK anti-terror measures: Read Theresa May's speech in full But as the IRA once boasted, the terrorists "only have to be lucky once." And last year, Drummer Lee Rigby was murdered in broad daylight by Islamist extremists in London, while Mohammed Saleem, an 82-year old British Muslim from Birmingham, was murdered by a Ukrainian far right extremist who then tried to bomb mosques in Walsall, Wolverhampton and Tipton. The terrorists who committed these cowardly acts are now where they belong, behind bars serving life sentences. But since the attacks they carried out, the threat we face from terrorism has grown more serious. Drummer Lee Rigby of the Royal Regiment of Fusiliers, a British Army soldier, was attacked and killed by two men near the Royal Artillery Barracks in Woolwich, southeast London. This summer, JTAC - the Joint Terrorism Analysis Centre - raised the threat level for international terrorism from "substantial" to "severe." This means that JTAC believes an attack on the United Kingdom is highly likely. The decision to change the threat level was based primarily on developments in Syria and Iraq, where the terrorist group ISIL controls swathes of territory. We believe more than 500 British nationals have travelled to Syria and Iraq, many of them to fight. And they have been joined by people now totalling thousands from other European and western countries. ISIL and its western fighters now represent one of the most serious terrorist threats we face. They have shown their brutality, by murdering, raping and torturing men, women and children in the territories they hold, and by murdering western hostages - including British citizens - in the most savage way imaginable. One of their terrorists has already struck in Europe, when earlier this year he murdered four civilians outside the Jewish Museum in Brussels. And ISIL have made no secret of their desire to bring death and destruction to the United Kingdom, the United States and to other western countries. Unlike other terrorist organisations, ISIL have the ambition to become a state in their own right, with all the financial clout and the military and technological possibilities statehood brings. They occupy around a third of the combined territories of Syria and Iraq, a land mass almost the same size as Great Britain. And their geographical location means that they are just a few hours flying time away from our country. Their sophisticated use of the internet and social media means they have a significant propaganda reach right across the world. And there is evidence that as well as inspiring many young Muslims to travel to Syria and Iraq to fight, they have given energy and a renewed sense of purpose to subversive Islamist organisations and radical leaders in Britain. Abubakar Shekau, Boko Haram's leader, presents just one of the many terror threats to the UK So the threat ISIL presents to us is clear, and it is serious. But it is not the only threat we face. There is Boko Haram in Nigeria, Al Qaeda in the Arabian Peninsula in Yemen, related organisations in Libya, Al Shabaab in East Africa, terrorists planning attacks from Pakistan and Afghanistan, and home-grown extremists who have been radicalised here in Britain. The threat is diverse and - partly because of events on the ground across the Middle East - it is changing rapidly. As I said in a speech here at RUSI in 2011, at the beginning of the so-called Arab Spring, "change for the better is not inevitable ... There is a chance that the Arab Spring does not bloom; that new repressive regimes replace old ones; that they give way to new and more dangerous regimes; or that terrorists gain the space and power that they lacked under the autocratic regimes of the past." Unfortunately, that cautious warning has been proved right. Al Qaeda in the Arabian Peninsula operates within what is effectively a safe haven in parts of Yemen. Libya has not become more stable since the overthrow of Colonel Gaddafi, but less stable and more violent. Syria and Iraq have become the crucible of terror and violence in which groups such as Al Nusrah Front and ISIL operate. Away from the Middle East, Al Qaeda in the Maghreb has become more confident, using the capabilities it has developed through kidnap ransoms and weaponry seized in Libya. Al Shabaab has become more daring, most notably in its attack on the Westgate shopping mall in Nairobi and the cold-blooded murder of bus passengers in Northern Kenya. And Boko Haram has grown in size, strength and the extent of the territory it controls. Hundreds of newly trained al-Shabab fighters perform military exercises Some of these organisations may sound remote and distant, but each one of them has ambitions to strike at our citizens and our interests, and each represents a real threat to our national security. As Home Secretary, I am responsible for government policy on crime, policing, immigration and border control, but by far the most important of my responsibilities relate to counter-terrorism. This is actually the most intensive and time-consuming part of the job, yet for obvious reasons it is also the least well known and least understood. Almost every day I receive an intelligence briefing prepared for me by security officials that details threats to the UK and our efforts to counter them. On a typical day I spend considerable time carefully considering the necessity and proportionality of applications for warrants related to national security and serious crime. These are applications made by the Security Service, the National Crime Agency and the police to use interception and intrusive surveillance techniques to gain vital intelligence in the highest priority operations. Each week, I have a meeting in which I am briefed by the Security Service and, because they head up national counter-terrorism policing, the Metropolitan Police. This meeting is usually with the Director General of MI5 and the Met's Assistant Commissioner for Counter-Terrorism, and we cover a range of operational, legal and policy issues relating to the most serious terrorist threats we face. I also chair the weekly security meeting, in which I review the work we're doing to protect the public from the risk of a terrorist attack. May has weekly meetings with the head of MI5, Andrew Parker, on operational, legal and policy issue for the UK's most serious terror threats Around the table at the weekly security meeting sit representatives from MI5, MI6, GCHQ, JTAC, the Metropolitan Police, the Office for Security and Counter Terrorism, Border Force and organisations like the National Offender Management Service. Government departments that play their part in delivering our counter-terrorism strategy - including the Foreign Office, the Ministry of Defence, the Cabinet Office, the Treasury, the Northern Ireland Office, and the Departments for Education, Communities and Local Government, International Development and Transport - all attend too. The reason I am providing these details is that they illustrate the amount of time and effort devoted to counter-terrorism in government, and they show how many organisations need to be involved to deal with such a complex threat. There are threats from around the world and threats originating at home. Threats to British interests overseas and threats right here on our streets. Threats that relate not just to Islamist extremism - although that is by far the most dangerous - but from the far right, Northern Ireland-related terrorism, and others. Plots that aim to kill hundreds and even thousands of people, and plots that target specific victims because of who they are and what they stand for. Plots that try to wreak enormous damage on our economy. Cyber threats from hostile foreign states and from terrorist organisations. Radicalisation taking place behind closed doors in mosques, homes and community centres, but also in schools, universities and prisons. Hateful, radicalising propaganda disseminated in full view online and via social media. And serious attack planning, conducted online, too often protected by everyday technology from the watchful eyes of the intelligence agencies. Home Secretary Theresa May speaking at the counter terrorism event in London So this is a struggle that is being fought on many fronts and in many forms. And we therefore need a counter-terrorism strategy that is comprehensive and coherent. The strategy we inherited from the last government was, as I have said many times before, broadly sound. On coming to power we conducted a review of counter-terrorism powers and while we made some specific policy changes, the fundamental strategy stayed in place. Despite the debt crisis, we protected the budgets for counter-terrorism policing and for the security and intelligence agencies. We reduced the legal limit for pre-charge detention from 28 to 14 days. And we replaced control orders, which had been whittled down by the courts, with TPIMs, or Terrorism Prevention and Investigation Measures. Our biggest criticism of the last government's policy was that it had not done enough to counter the wider extremism - often not violent in its nature - that we believe is indelibly linked to the violence and terrorism that threatens us. We therefore reformed the "Prevent" pillar of the counter-terrorism strategy significantly. We separated Prevent work from the integration work that is led by the Department for Communities and Local Government. We made sure it would tackle all forms of terrorism, not just Islamist-related terrorism. We introduced new procedures to make sure we only work with organisations that respect British values and public funding does not find its way to extremist organisations. Most importantly, we changed Prevent's objectives so it deals with non-violent extremism as well as violent extremism. Theresa May said the government responded to the murder of Lee Rigby by setting up the Extremism Task Force We always said we would keep our terrorism laws and capabilities under review, so we are able to respond to events, new emerging threats and different methods used by our enemies. We learned from the 7/7 inquests the need for much better interoperability between the emergency services. We learned too from the marauding attacks in Mumbai in 2008. We responded to the murder of Lee Rigby by setting up the Prime Minister's Extremism Task Force. And there will, no doubt, be important lessons in the report by the Intelligence and Security Committee about Lee Rigby's murder, which will be published very soon. We have worked hard to make it easier to get rid of foreign nationals, including terrorists and terror suspects, who should not be in this country. We have changed the law to make clear to the courts that Article Eight of the European Convention on Human Rights, the right to a family life, is a qualified and not an absolute right. We have changed the law to reduce the number of appeal rights in immigration law from seventeen down to four. And we now have six "deportation with assurance" agreements with countries including Jordan and Morocco so we can deport people in line with our human rights obligations. We have legislated, through the Justice and Security Act, to allow the use of closed material procedures in some civil cases so the courts can provide justice where sensitive information relating to national security is central to the case. We made sure, even as we opted out of more than 130 European measures, that we signed up to measures like SIS II, or the second generation Schengen Information System, which will allow us to track foreign fighters and terror suspects. We have legislated to deprive naturalised Britons of their citizenship when we believe they can acquire another nationality. In the Serious Crime Bill, we are making it a criminal offence to prepare and train for terrorism abroad. And we are continuing our work that will lead to the introduction of exit checks at the border by April next year. Hyde Park memorial to victims of the 7 July 2005 London bombings This summer we also changed the law, with cross-party support, to deal with two urgent problems relating to communications data and interception. When the European Court of Justice called into question the legal basis upon which we require communication service providers to retain data, and when providers based overseas questioned the application of our laws on interception to them, we legislated to put both questions beyond doubt. I am not going to pretend that it has been all plain sailing. As Home Secretary, I have, almost from day one, made the case for the police and security services to be given full access to the communications data they need to keep us safe. For years, they have had access to this data - the "who, where, when and how" of a communication but not its content - and it has played a significant role in every major Security Service counter-terrorism operation in the last decade. But because the way in which we communicate is increasingly online, the ability of the authorities to obtain the data they need is declining rapidly. Unfortunately there is no agreement in the Coalition - or for that matter with the Opposition - about the need for the Communications Data Bill, and so we are going to have to wait until after the general election to address fully this increasingly urgent problem. But I remain passionately convinced that our national security - not to mention our ability to fight back against organised crime groups and networks of child abusers - means we need this Bill. But despite this difficulty, we have built on the broadly sound strategy we inherited from the last government and we have a strong record when it comes to giving the police and security services the powers and resources they need to keep us safe. Radical muslim cleric Abu Hamza is one of the 13 to have been extradited To put things into perspective, I will tell you about the range of actions that the authorities have taken since May 2010. I have already said that in this period our country has faced numerous terrorist plots. But since April 2010, 753 people have been arrested for terrorism-related offences. 212 have been charged and 148 have been successfully prosecuted. 138 people are behind bars serving sentences for terrorism-related offences. Thirteen people, including Abu Hamza, have been extradited after being accused or convicted of terrorism-related offences. We have also made sure that a number of dangerous people, including Abu Qatada, have been removed from this country because of the terrorist threat they posed. Since the start of this government, the Counter-Terrorism Internet Referral Unit has secured the removal of 65,000 items from the internet that encouraged or glorified acts of terrorism. More than 46,000 of these have been removed since December last year. At present, content relating to ISIL, Syria and Iraq represents around seventy per cent of the Unit's caseload. Since I became Home Secretary, I have excluded hundreds of people in total from Britain. I have excluded 61 people on national security grounds and 72 people because their presence here would not have been conducive to the public good. In total, I have excluded eighty-four hate preachers. Seventy four organisations are at present proscribed because they are engaged in or support terrorism. Since May 2010 I have revoked the British citizenship of twenty-seven people because their activities were not conducive to the public good, the overwhelming majority because of terrorist activities. And since I updated the criteria for using the Royal Prerogative in April 2013, I have refused or cancelled 29 passports to disrupt the travel of people planning to engage in terrorist-related activity overseas. Abu Qatada was deported from Britain after a near-decade-long legal battle This is the scale of the threat we face and the scale of the work the authorities do every single day to keep the public safe. So when the security and intelligence agencies tell us that the threat we face is now more dangerous than at any time before or since 9/11, we should take notice. And - after careful analysis and thorough preparation - where we can tighten our laws and toughen the powers and capabilities available to us, we should. I can therefore confirm, as the Prime Minister first announced this summer, the Government will on Wednesday introduce a new Counter-Terrorism and Security Bill. In common with all the work the Government has done since May 2010, this legislation will seek to build on our existing counter-terrorism strategy. The new powers will help us to prevent radicalisation, strengthen the TPIMs regime, give us greater powers to disrupt and control the movements of people who go abroad to fight, improve our border security, make sure British companies are not inadvertently funding ransom payments, close down at least part of the communications data capability gap, and establish a new independent privacy and civil liberties board. First, radicalisation. I've already explained how we have reformed the Prevent programme, but - as I have said before - there is always more to do and we need to go further. So we will legislate to put Channel - the existing successful programme for people at risk of radicalisation - on a statutory basis to improve the consistency of its delivery and ensure the participation of all the appropriate organisations. Aqsa Mahmood, 20, (left) at a family wedding, Aqsa is a "bedroom radical" who travelled to Syria and married an Isis fighter after she left her Glasgow home We will also place a statutory duty on named organisations - such as schools, colleges, universities, the police, prisons, probation providers and local government - to help prevent people from being drawn into terrorism. So for example universities will have to put in place extremist speaker policies and prisons will have to show they are dealing with extremist prisoners in an appropriate way. The organisations subject to the duty will have to take into account guidance issued by the Home Secretary. Where organisations consistently fail, ministers will be able to issue directions to them - which will be enforceable by court order. The Bill will also strengthen the TPIM regime. TPIMs give the police and security services strong legal powers to disrupt and restrict the movements of terror suspects and their contact with named associates when we cannot disclose sensitive intelligence material in an open court or if they are a foreign national we are unable to deport. They enable the authorities to limit a subject's access to telephones and the internet, prevent them meeting certain associates, compel them to stay at a named address for a set number of hours every day, and bar them from entering certain premises or neighbourhoods. The overall package - which in addition to these legal powers gave the police and Security Service tens of millions of pounds for increased surveillance and investigation - remains sound. But in response to the increased threat we face and in response to the police and security services telling us this is what they need, we will legislate to allow TPIM subjects to be relocated to different parts of the country. At the same time we will accept the recommendation made by David Anderson, the independent reviewer of terrorism legislation, that the burden of proof for TPIMs should be raised from "reasonable belief" to the "balance of probabilities." This is in line with the civil standard of proof and our analysis shows that every single TPIM issued so far would have passed this threshold. Sir Bernard Hogan-Howe is Britain's most senior police officer, and authorities will be given greater powers to control the movements of suspected terrorists The Bill will give the authorities greater powers to disrupt and control the movements of people who want to travel abroad to fight. The police - and designated Border Force officers acting on the directions of the police - will have the power to seize somebody's travel documents, which includes tickets as well as passports, at the border for up to thirty days if they have reasonable suspicion that a person plans to leave the UK for the purpose of engaging in terrorism-related activities. This power will apply to British passports and foreign passports and to British citizens and foreign nationals. And it will give the authorities time to investigate the suspect and assess whether they need to take further action. In addition to these new powers to stop people leaving the country, the Bill will create a statutory Temporary Exclusion Order to control the return to the UK of a British citizen suspected of involvement in terrorism-related activity abroad. These orders will be enforced through the cancellation of travel documents and the inclusion of the individual's details on our watch lists, including the "no-fly" list. So the message to British nationals participating in terrorism overseas is clear: you will only be allowed to come home on our terms. We are also taking the opportunity to toughen our arrangements for aviation security. This means requiring airlines to provide passenger data more effectively, changing the law to extend our "no-fly" list, and strengthening our ability to impose security and screening requirements on travel to the UK. If airlines do not give us passenger information or comply with our security screening rules, we will ensure they cannot fly to the United Kingdom. A stil from a propaganda video released by Isis To put an end to uncertainty about insurance and reinsurance payments for kidnap and ransom, and to help prevent an important element of terrorist financing, the Bill will amend existing law to make sure UK-based insurance firms do not provide cover for the payment of terrorist ransoms. To put this important issue into context, along with oil sales, taxation and extortion, the UN estimates that ransom payments raised up to £28million for ISIL in the last twelve months alone. A new offence will apply to ransom payments once the Bill is introduced. As I have already said, I remain passionately convinced of the need to address the capabilities gap the authorities face when it comes to communications data. And I am pleased to say that the Bill will go some way to bridging that gap. It will therefore require internet providers to retain Internet Protocol - or IP - address data to identify individual users of internet services. This is an important step and it builds on the emergency legislation in the summer. But I must emphasise that these powers are limited and they do not mandate the retention of and access to data that would in all cases identify a suspect who has, for example, been accessing servers hosting illegal content. The progress in this Bill is welcome - but we will still need to return to the Communications Data Bill in the next Parliament. Home Secretary Theresa May: 'This legislation is important' The powers in the Counter-Terrorism and Security Bill are essential to keep up with the very serious and rapidly changing threats we face. But it is also right that we make sure there is proper oversight and scrutiny of those who use the sensitive powers granted by counter-terrorism legislation. That is why we have already acted in this Parliament to strengthen the role and increase the resources available to the Intelligence and Security Committee. And it is why the Bill will also establish a new independent privacy and civil liberties board to support the Independent Reviewer of Terrorism Legislation, David Anderson QC. This legislation is important. The substance is right. The time is right. And the way in which it has been developed is right. It is a properly-considered, thought-through set of proposals that will help to keep us safe at a time of very significant danger. It builds on a successful strategy. It goes with the grain of existing policy. It has been drawn up in close consultation with the police and security services. It is deliberately focused on practical measures that we can be confident will work. And it broadly commands cross-party support. In an open and free society like ours, we can never entirely eliminate the threat from terrorism. But we must do everything possible, consistent with our values as a country, to reduce the risk presented by our enemies. The Government's policy, our counter-terrorism strategy and this legislation all aim to do just that. We are engaged in a struggle that is fought on many fronts and in many forms. It is a struggle that will go on for many years. And the threat we face right now is perhaps greater than it ever has been and we must have the powers we need to defend ourselves.