US Edition The ICM survey for The Sunday Telegraph provides headaches for both David Cameron and Alex Salmond, Scotland's First Minister, as the battle ahead of a referendum on the future of the 307-year-old Union heats up.
In a landmark intervention, the Prime Minister used an interview with this newspaper last weekend to call Mr Salmond's bluff over a referendum, demanding one "sooner rather than later" and claiming that the uncertainty surrounding the polling plans was harming Scotland's economy.
Mr Salmond, whose Scottish National Party (SNP) has a majority in the Scottish parliament, responded by saying there would be a referendum in 2014, the 700th anniversary of the Battle of Bannockburn.
The poll shows that while a substantial proportion of Scots (40 per cent) back independence, 43 per cent want to remain inside the United Kingdom.
However, among English voters - who would not get a vote in any referendum - there is a clear lead for those who support independence for Scotland (43 per cent) over those who want the Union to be preserved (32 per cent).
In a similar ICM survey for The Sunday Telegraph in December 2006, voters in both England and Scotland were in favour of Scottish independence,
Today's poll provides a series of setbacks for Mr Salmond, who favours a "three question" referendum in which Scots are offered the choice of full independence, the status quo, or a "devolution max" option in which all powers other than foreign policy and defence are handed to the parliament in Edinburgh.
Offered this precise choice by ICM, more Scots go for the status quo (37 per cent) than the other two options, both of which win 26 per cent support.
Mr Salmond's choice of a referendum in 2014 is also less popular (41 per cent) among Scots than a vote "as soon as possible (43 per cent). More than half English voters (52 per cent) also want a quick referendum.
Most Scots admit their nation would be worse off after independence (41 per cent) than better off (38 per cent), while 51 per cent of English think the Scots would be worse off.
Mr Cameron, who makes it clear he is a passionate defender of the Union, faces a fight to turn round public opinion south of the border, however.
As well as clear support for Scottish independence, just under half of English voters (49 per cent) back the creation of an English parliament, with only 16 per cent against – a lead which is down slightly on 2006.
Some 61 per cent of English people, moreover, say the current formula which sees higher government spending per head in Scotland is unjustified - a similar finding to 2006.
Among Scots, 53 per cent think that the spending system, known as the Barnett formula, is justified while 21 per cent do not agree.
If Scotland votes for independence the country is likely to have to apply to join the euro and would see the Trident nuclear weapons system, whose home currently is Faslane on the Clyde, repatriated south of the border.
Nationalist politicians have attacked Mr Cameron for "bullying" Scots over an independence vote.
Stewart Hosie, the SNP MP who is his party's chief whip at Westminster, said: "Every step the anti-independence parties have taken since Cameron's chaotic intervention ... has done nothing but boost support for independence and ensuring that the people of Scotland are able to see decisions taken about what's best for Scotland in Scotland."
All three major parties in England – the Conservatives. Labour and the Liberal Democrats – believe in keeping the Union Kingdom together, but the nascent pro-Union campaign suffers from the lack of a clear leader to puts the case forcefully against Mr Salmond.
The Conservatives only have one MP in Scotland – ruling out Mr Cameron or George Osborne, the Chancellor – while no senior Labour politician appears to relish taking up the role.
Alistair Darling, the former chancellor, emerged last week as a possible candidate but he is understood to have told colleagues he is reluctant to take on the position.