Ed Miliband today issues the stark threat that manned border posts could be introduced if Scotland backs independence in next week's historic vote. 
 
 With just 11 days to go until the referendum - and polls showing growing momentum for Alex Salmond's nationalists - the Labour leader has urged voters to face up to the consequences of severing the 300-year-old Union. 
 
 'If you don't want borders, vote to stay in the United Kingdom,' Mr Miliband said in an interview with today's Scottish Mail on Sunday. 
 
 Scroll down for video 
 
 Passport please: Our artists' impression of a road border between England and Scotland post-independence 
 
 Asked whether that would mean him introducing border guards and passport checks if he was Prime Minister, Mr Miliband warned: 'It would have to be looked at.' 
 
 And Mr Miliband's spokesman added last night: 'The last time I looked there were two sides to the border - and we would be in charge of one of them. It would be up to us, not Mr Salmond, to secure our northern border.' 
 
 The prospect was raised as a shock poll showed that 51 per cent of Scots would vote ‘Yes’ to going it alone with just 49 per cent saying ‘No’. 
 
 The results of the YouGov survey means that the ‘Yes’ campaign has overturned a 22-point lead within a month. 
 
 Until now, Mr Salmond’s SNP has insisted that a separate Scotland would be part of a common, free movement area with the rest of the UK and Ireland. 
 
 Guards on the border: Where the controls could be placed if Scotland wins independence in 11 days' time 
 
 But a Downing Street source backed Mr Miliband, saying: ‘All the research shows that if there is a material difference between the immigration policy adopted by an independent Scotland and the rest of the UK, then border controls would have to be introduced.’ 
 
 It raises the extraordinary prospect of drivers having to stop at manned barriers on the borders to show their passports. 
 
 SCOTS FOOTBALL LEGENDS JOIN CALLS FOR PATRIOTS TO SAY 'NO' Soccer pundit Alan Hansen and a ‘squad’ of great Scottish footballers from all eras of the game have called on ‘every patriotic Scot’ to vote No to independence. The other players who signed up to a statement are: Alex McLeish, Jim Leighton, David Moyes, Willie Miller, Paddy Crerand, Davie Provan, Barry Ferguson, Bertie Auld, Denis Law, Ally McCoist, Derek Johnstone, Murdo MacLeod, Ian Durrant, John Brown and Frank McAvennie. 
 
 With the latest opinion polls showing Mr Miliband on course to win May’s General Election, a Labour Government could be in charge of negotiating Scotland’s passage to independence by March 2016 if the referendum returns a ‘Yes’ vote. 
 
 The SNP dismissed the idea of border controls as a ‘scare story’, but Mr Miliband’s advisers say it is not an idle threat: a secret memo drawn up by the Foreign Office in 2009 warned that a secure border would have to be established to protect the ‘remaining UK’ if an independent Scotland applied to join the EU. 
 
 All new EU members are obliged to accept the Schengen open borders scheme, meaning travellers from the continent would be free to fly into Scotland without immigration checks. 
 
 But Britain has opted out of the scheme, and erects border controls to vet travellers from Schengen countries, raising the prospect of a new Hadrian’s Wall between the two nations. 
 
 New border posts would cause chaos for travellers and prove to be hugely damaging to business. 
 
 The 95-mile border, which runs from Lamberton on the east coast to the Solway Firth in the west, cuts through 21 roads, including two major trunk routes, the A1 and M74. 
 
 No idle threat by Mr Miliband: A memo drawn up by the Foreign Office in 2009 warned that a secure border would have to be established to protect the ‘remaining UK’ if an independent Scotland applied to join the EU 
 
 A total of 23 million vehicle crossings a year are made on the roads, in addition to seven million passenger journeys on the West Coast and East Coast railway lines. 
 
 If controls were set up, immigration staff could man barriers on the roads while the train terminals would have to install checks similar to those adopted by Eurostar. 
 
 Last night former Labour Home Secretary David Blunkett echoed Mr Miliband’s warning by referring to last week’s riots in Calais when immigrants attempted to storm a ferry. 
 
 ‘Were the Scots to vote “Yes” to separation, the issue of border controls and the threat of entry through Scottish ports and airports would take on serious proportions,’ Mr Blunkett told The Mail on Sunday. 
 
 Support for Alex Salmond's camp has soared, with a poll last night putting the Yes vote on 51 per cent 
 
 ‘This is one issue that has not yet emerged as a key part of the debate over Scotland’s future. There is much at stake and little sign of Government action in response.’ 
 
 Panic spread through the ‘No’ campaign last week after an opinion poll showed that its lead over the nationalists had shrunk to just six points, with support for Mr Salmond’s position up by eight points in a month. 
 
 Mr Cameron is happy to let Mr Miliband make the running for the pro-Union campaign as Labour supporters make up a large proportion of the ‘undecided’ voters. 
 
 The Prime Minister paid his annual visit to the Queen at Balmoral yesterday, but accepted the advice of Palace aides not to join her at the Braemar Games in case it was seen as ‘politicising’ the Monarch. 
 
 It is also in Mr Miliband’s interest to defeat the nationalists: if Scottish voters had been excluded from the last Election, Mr Cameron would have won a clear Westminster majority without the need for a Coalition. 
 
 The scale of Labour fears over a possible ‘Yes’ vote was laid bare yesterday when the party’s English and Welsh MPs were told to get up to Scotland to save the Union. In an email to all Labour MPs, Chief Whip Rosie Winterton revealed that Labour had booked scores of train tickets to get them to go north of the border before the referendum. 
 
 In his interview, Mr Miliband also mentioned his ‘personal connection’ with Scotland – his father, Ralph, was stationed at Inverkeithing, Fife, during the Second World War. ‘The rest of the UK would be much weaker without Scotland. It matters for reasons of heart and for head,’ he said. 
 
 Former Liberal Democrat leader Charles Kennedy urged fellow ‘No’ campaigners to hold their nerve, saying: ‘There is a flavour of detail and substance being swept aside in a tide of emotion and exclusive patriotism. It is a dangerous time for the No campaign.’ 
 
 Asked about Mr Miliband’s remarks, a spokesman for Yes Scotland said: ‘There will be no border posts between an independent Scotland and the rest of the UK. 
 
 ‘The No campaign will say anything to try to scare people into throwing away this unique opportunity to put our future into our own hands. They’ll always put what’s right for Westminster above what’s best for Scotland. Border posts manned by guards take the prize for one of the sillier scare stories.’ ||||| EDINBURGH British Prime Minister David Cameron on Wednesday begged Scots not to rip apart the United Kingdom's "family of nations", flying to Scotland to man the barricades against a surge in support for independence eight days before a referendum. 
 
 Cameron appealed to Scots to use their heads and their hearts when they voted on Sept. 18. He reminded them of their shared history and bonds with England, Wales and Northern Ireland - twice evoking World War Two and the fight against Hitler. 
 
 He also warned that an independent Scotland could not keep the pound currency, jobs would head south, and the country's security be weakened. 
 
 "I would be heartbroken if this family of nations was torn apart," said Cameron, speaking to staff of the Scottish Widows financial institution in the capital Edinburgh. 
 
 Cameron's visit was a sign of the panic that has gripped the British ruling elite over the possible disintegration of the 307-year-old union since two polls in the past showed the campaign for independence, led by Alex Salmond's Scottish National Party, gaining support to run neck-and-neck with the "No" campaign, which until a few weeks ago was looking comfortably ahead. 
 
 There was some relief for unionists when a poll released on Wednesday evening showed 53 percent of Scots would vote against a split, with 47 percent intending to opt for independence - unchanged from its last survey on Aug. 28. 
 
 The figures from the poll, carried out by Survation for the Daily Record newspaper, excluded 10 percent of undecided. 
 
 British deputy prime minister Nick Clegg, who leads the Liberal Democrats, and opposition Labour Party leader Ed Miliband also crossed the border on Wednesday to shore up support. All three parties have offered Scotland greater autonomy as an enticement to vote against independence. 
 
 The prime minister, whose job may be on the line if he loses Scotland, warned Scots a vote for secession would be forever. 
 
 "I think people can feel it is a bit like a general election, that you make a decision and five years later you can make another decision if you are fed up with the effing Tories, give them a kick and then maybe we'll think again. This is totally different to a general election: this a decision about not the next five years but a decision about the next century," he said. 
 
 Cameron has until now been largely absent from the debate after conceding that his privileged background and centre-right politics mean he is not the best person to win over Scots, who returned just one Conservative lawmaker out of 59 in 2010. 
 
 He made no street appearances in his visit to Edinburgh. 
 
 "David Cameron is a swear word up here," said one security guard, asking not to be named. 
 
 That comment echoed the sentiment among pro-independence Scots that they are ruled from London by a government they did not choose - a central tenet of the independence drive. 
 
 The "Yes" camp says it wants to build a fairer society with Scotland's interests at the forefront. Opponents of independence say Scotland is stronger and more secure within the United Kingdom, and a separate country would struggle economically. 
 
 BEST OF BOTH WORLDS? 
 
 The ramifications of a split could be immense given the United Kingdom's position as a G8 economy, a leading member of NATO and the European Union, and permanent member of the U.N. Security Council. U.S. President Barack Obama and other world leaders have said they want Britain to stay together. 
 
 Cameron held out the promise of more power for Scotland if Scots voted "No". 
 
 "It really will be the best of both worlds," he said. 
 
 "Scotland is a nation, an incredible nation, strong, proud, with an extraordinary history but also part a family of nations. Please don’t think that the rest of the United Kingdom is indifferent. We care passionately." 
 
 Salmond said the visits were a sign of panic that would only help the secessionist cause. Independence supporter James Curry, 33, said in Edinburgh he found the visits by politicians from London "insulting and patronizing". "They should've been up here ages ago. Instead, they're having a wee day trip," he said. "There's so much at stake, and it seems so real‎ already, I just hope we make it." 
 
 Labour's Miliband meanwhile went to the town of Cumbernauld to campaign for Scotland staying in the union. 
 
 Labour supporters are seen as a vital constituency in the fight, given the dearth of Conservatives in Scotland, and if enough reject the party line it could tip the balance. 
 
 The loss of Scottish Labour MPs in Westminster should Scotland become independent would also seriously affect its election prospects south of the border. 
 
 Miliband promised that Labour would meet Scottish aspirations for a just, fairer society. He said working-class solidarity went across the border and noted that six Scottish trade unions had come out against independence. 
 
 "The people of Scotland, whether they intend to vote no or yes, have established beyond doubt in this campaign that there needs to be profound economic and political change. This thirst for change is shared across the United Kingdom." 
 
 Saying that his father served in Scotland in World War Two, Miliband said. "So many, across the United Kingdom, will have their own connections of friendship and family with Scotland ... Please stay with us." 
 
 The surge in support for independence over recent weeks has also discomfited investors. Sterling hit a 10-month low against the dollar and a three-month low against the euro on Wednesday, with traders citing an unverified web poll conducted by a blogger that gave the "Yes" camp a strong lead. 
 
 Some major companies with Scottish exposure cautioned about the risks of secession: Standard Life said it could transfer business to England, while BP CEO Bob Dudley said the future of North Sea oil was best served by keeping the United Kingdom together. 
 
 Following a vote for independence, London and Edinburgh would face 18 months of talks on how to carve up everything from North Sea oil and the pound to EU membership and Britain's main nuclear submarine base at Faslane. 
 
 Bank of England Governor Mark Carney said that a new central bank in and independent Scotland would need big stockpiles of sterling if the country opted to adopt the pound without an agreement with the rest of the United Kingdom. He also said it was likely that economic borders would build up between an independent Scotland and the rest of the UK. 
 
 STREET TALK 
 
 The referendum - the biggest internal challenge to the United Kingdom since Irish independence almost a century ago - has electrified Scotland. On streets, in pubs and in meeting halls from the Highlands to the windswept islands of the Atlantic, independence is being debated with passion. 
 
 Bookshops are full of referendum guides and tracts for and against. The Scotsman newspaper published six pages of letters on the vote on Wednesday. 
 
 "Do we wish to become a small, successful, independent state free to develop our own way of life and find our way in the family of nations? Or would we rather continue as a small appendage of a once glorious but now declining power punching above our weight in hopeless wars like Afghanistan ... while at home constructing one of the most unequal societies in the world," wrote "Yes" supporter John Slee of Gullane. 
 
 Other letter writers said the SNP’s economic figures just didn’t add up, particularly the funding for public spending. 
 
 "The 'Yes' campaign’s spin doctors are successfully piping our economy off a cliff," wrote Hugo Cannon of Edinburgh. 
 
 (Additional reporting by Guy Faulconbridge, Michael Holden, Kate Holton, Andy Bruce, Kylie MacLellan and Jemima Kelly in London and Alistair Smout in Edinburgh; Editing by Will Waterman) ||||| Media playback is unsupported on your device Media caption Campaigners for and against Scottish independence say every vote will count as opinion polls suggest the race is neck and neck, as James Cooke reports 
 
 Campaigners in the battle for Scotland's future say the referendum result is too close to call with less than two weeks until the vote. 
 
 The Yes camp claims to have the "big momentum" behind it, while opponents of independence insist they will win. 
 
 It comes as one poll put Yes Scotland narrowly ahead for the first time. 
 
 Responding to the poll, UK Chancellor George Osborne pledged that in the next few days there would be a plan for more powers for the Scottish Parliament. 
 
 Scottish First Minister Alex Salmond branded the suggestion a "panicky" bribe, coming after thousands of people had already voted by postal ballot. 
 
 With just 11 days of campaigning left, both sides are stepping up their bids for the wavering voters who could yet sway the result. 
 
 VIDEO: Campaigners make pitch to voters 
 
 Media playback is unsupported on your device Media caption George Osborne said an action plan would provide ''the best of both worlds'' 
 
 Media playback is unsupported on your device Media caption Alex Salmond: ''The whole Westminster elite are losing the referendum campaign'' 
 
 On 18 September voters will be asked the Yes/No question: "Should Scotland be an independent country?" 
 
 The final push for votes comes as a a YouGov poll for the Sunday Times suggested that, of those who have made up their mind, 51% planned to back independence, while 49% intended to vote no. 
 
 The poll of 1,084 people, carried out between 2 and 5 September, is the first and only serious study to put the Yes campaign ahead. 
 
 The cross-party Better Together campaign - which supports the Union - had previously retained a lead in polls, often reaching double digits. 
 
 However, a separate poll for the Yes Scotland campaign put the pro-Union camp four points ahead - by 52% to 48% - when undecided voters were excluded. 
 
 Pollsters Panelbase questioned voters between 2 and 6 September. 
 
 Writing in the Sunday Mirror, former Labour Prime Minister Gordon Brown appeared to blame the Conservative Party for the closeness of the battle. 
 
 He suggested the Better Together camp was finding it "difficult" to win over Scots because of anger over coalition policies - including changes to housing benefit and tax cuts for the wealthy. 
 
 A referendum on whether Scotland should become independent is to take place 
 
 People resident in Scotland will be able to take part in the vote, answering the "yes/no" question: "Should Scotland be an independent country?" 
 
 The referendum will take place on Thursday, 18 September 2014 
 
 Go to the BBC's Scotland Decides page for analysis, background and explainers on the independence debate. 
 
 Better Together campaign leader Alistair Darling said the findings were a "wake-up call". 
 
 "The polls may conflict," Mr Darling said. "But the message I take from them is clear - if you want Scotland to remain part of the UK family you have to vote for it on 18 September. 
 
 "Separation is forever." 
 
 And while he insisted "this is a battle we will win", the former chancellor said the result would "go down to the wire". 
 
 'Work better' 
 
 Commenting on the Sunday Times poll, Deputy First Minister Nicola Sturgeon said: "This breakthrough poll shows that Yes has the big momentum." 
 
 "Scotland is one of the wealthiest countries in the world," she added. 
 
 "More and more people are beginning to realise that a Yes vote is Scotland's one opportunity to make that enormous wealth work better for everybody who lives here, create more jobs, and protect vital services such as the NHS from the damaging effects of Westminster privatisation." 
 
 But the SNP's deputy leader acknowledged the Yes campaign "still has a lot of work to do". 
 
 Image copyright PA Image caption Ms Sturgeon visited Glasgow Central Mosque on the campaign trail on Friday 
 
 The Sunday Times poll results exclude undecided voters or those who plan not to vote. 
 
 When they are included, 47% backed Yes while 45% said they would opt to stay in the UK. 
 
 Responding to the polls, a Downing Street source said David Cameron believed there was "only one poll that matters". 
 
 The prime minister would "strain every sinew" to make the case for the union, the source added. 
 
 On Sunday's Andrew Marr Show, George Osborne promised further powers to Scotland if there is a No vote. 
 
 He said: "You will see in the next few days a plan of action to give more powers to Scotland, more tax powers, more spending powers, more powers over the welfare state. 
 
 "That will be put into effect the moment there is a 'No' vote in the referendum." 
 
 However, speaking on the BBC's Sunday Politics Scotland, Mr Salmond called the new proposal a "bribe". 
 
 He said: "Are we expected to believe, after hundreds of thousands have already voted, that there's a radical new deal? 
 
 "This is a panicky measure made because the 'Yes' side is winning on the ground." 
 
 He added: "They're trying to bribe us, but it won't work as they have no credibility left." 
 
 Analysis 
 
 John Curtice, professor of politics at Strathclyde University 
 
 At first glance today's two referendum polls tell much the same story. One, YouGov, says that the Yes side is narrowly ahead, while the other, Panelbase, says it is only just behind. Both polls are thus effectively saying that the referendum now looks too close to call. 
 
 But look a little closer and we see a remarkable difference between the two polls. Four weeks ago, YouGov were reporting the No side were 22 points ahead. But since then three polls in succession have identified a continuing trend to Yes that cumulatively amounts to no less a 12 point swing. 
 
 In contrast, Panelbase, always hitherto the most optimistic pollster for the Yes side, first put Yes on 48% as long ago as June. It did the same just three weeks ago. In other words its poll has failed to detect any recent swing to the Yes side at all. 
 
 Given this contrast, until another pollster confirms that there has indeed been a substantial swing to Yes there will inevitably be some doubt about just how much the progress the Yes side has made. 
 
 That said, a majority of pollsters have said in their most recent poll that the Yes vote is now at least as high as it has been at any point during the campaign. The race certainly now looks tight - we are just as yet still not sure quite how tight. 
 
 Elsewhere, Labour leader Ed Miliband suggested in an interview with the Scottish Mail on Sunday that manned border guards could be introduced if Scotland voted to go independent. 
 
 He told the paper: "If you don't want borders, vote to stay in the United Kingdom." 
 
 A spokesman for Mr Miliband added: "The last time I looked there were two sides to the border - and we would be in charge of one of them. It would be up to us, not [First Minister Alex] Salmond, to secure our northern border." 
 
 The party later said on Twitter that there was "no Labour 'plan' for border guards in [an] independent Scotland". 
 
 Image copyright Clyde Blowers Image caption Pro-independence tycoon Jim McColl will write a letter targeting undecided voters 
 
 The two sides will intensify their efforts this week, with senior Labour Party figures including John Prescott and Welsh first minister Carwyn Jones due to appear for Better Together. 
 
 For the pro-independence camp, a Yes Scotland television advert focusing on the NHS will be broadcast on Monday, and on Tuesday Mr Salmond will answer questions from undecided voters on Facebook. 
 
 The Yes campaign also plans to send out 675,000 letters from engineering tycoon Jim McColl, who recently stepped in to save Ferguson Shipbuilders on the Clyde, urging undecided voters to support independence. 
 
 Mr Darling described the planned letter as "rank hypocrisy", arguing that Mr McColl was not based in Scotland. 
 
 He also criticised the nationalists over a Commons vote on controversial welfare reforms on Friday, from which four out of six SNP MPs were absent. 
 
 Image copyright Getty Images Image caption Labour's John Prescott and Welsh first minister Carwyn Jones will campaign for a "No" vote 
 
 Better Together will also step up its leafleting and young voters will receive personally addressed letters. 
 
 Labour MP Douglas Alexander said: "In the course of the coming days we will be joined by amongst others John Prescott, the former deputy prime minister, and Carwyn Jones, the first minister of Wales. 
 
 "All young voters across Scotland will get a personally addressed letter this week from Better Together. 
 
 "Over four million individually addressed pieces of communication started going out last week."
– Is the UK on the road to Splitsville? Scotland votes on independence on Sept. 18, and one poll has put the pro-independence "Yes" camp in the lead with 51% for the first time, the BBC reports. The "No" side was 22 points ahead less than a month ago, and Scottish National Party leader Alex Salmond accused British leaders of panicking as they unveiled proposals to give the Scottish parliament more powers if voters reject independence. Chancellor George Osborne promised that Scotland would be given more powers over things like tax rates and spending, the Guardian reports, but Salmond called the offer a bribe and said there is already a "radical new deal on the constitution—it's called independence." Yes campaigners have accused the No side of stepping up scare tactics in the lead-up to the vote, with Labour Party leader Ed Miliband warning that manned posts might be introduced along the border if Scotland decides to go it alone. "If you don't want borders, vote to stay in the United Kingdom," he told the Daily Mail yesterday.