Gordon Brown appeared to distance himself yesterday from the decision by Wendy Alexander, the leader of Scottish Labour, to change party policy north of the Border and back a snap referendum on independence.

A Downing Street spokesman said that the position taken by Ms Alexander was “a matter for her”, seeming to confirm Ms Alexander's high-stakes gambit, which could put the future of the UK at risk, has surprised the Prime Minister and had been adopted without his full backing.

Last night the apparent gulf between Downing Street and the party in Scotland became even wider when Ms Alexander's Labour MSPs at the Scottish Parliament, at their weekly meeting, gave her their support for the move and called on the minority SNP administration in Edinburgh to bring a Bill forward early. Ms Alexander said that she had not ruled out bringing forward Labour's own Bill at Holyrood and would be discussing this with other opposition parties in Scotland but insisted that the SNP should hold a referendum next year.

“It is unacceptable to allow this issue to remain unaddressed,” she said. “It is up to the SNP administration to bring this to an end.”

The Nationalists have reacted coolly to Ms Alexander's tactics saying that they have no intention of departing from their original intention of introducing legislation on a referendum in 2010.

The Downing Street spokesman said that there was a debate taking place in the Scottish Parliament on the timing of any potential referendum on Scottish independence.

“The position taken by the leader of the Scottish Labour Party is a matter for her ... the Prime Minister has always been confident of the strength of the argument in favour of the Union and believes a referendum on Scottish independence would be defeated,” he added.

However, this omitted any statement of outright support for Ms Alexander's manoeuvre raising the question of whether Mr Brown will maintain his present position. While he is said to welcome any move which puts pressure on Alex Salmond, Mr Brown apparently did not know that Ms Alexander, a long-time ally, intended to make public her shift of position in a television interview on Sunday.

Ms Alexander insisted again yesterday that discussions took place in the higher echelons over a period of time on support for a referendum although she would not directly answer the question of whether Mr Brown was on board for the U-turn.

Sources at Westminster have told The Times that Mr Brown and Ms Alexander have not discussed the issue of an independence referendum in the past few days. A Labour insider said: “If under his present tribulations he suddenly announced a referendum on independence for Scotland, the world would think he had taken leave of his senses.”

Until now, Scottish Labour, along with the Lib Dems and the Tories at Holyrood, have said that they will oppose any SNP Bill for a referendum, ensuring that because of the parliamentary arithmetic at Holyrood, it would be defeated. Ms Alexander changed all that in the last 72 hours when she made clear that she favoured a straight “yes/no” referendum and that one should take place before 2010 in order to end the uncertainty on the issue which was hanging over Scotland “like a spectre”.

Ms Alexander said: “I do not fear the verdict of the Scottish people. Bring it on.”

Her move was aimed at wrong-footing the Nationalists who want to use the opposition of the Unionist parties to a referendum as their main campaigning platform at the next Holyrood elections, claiming their opponents are denying the Scots their right to self-determination.

The referendum U-turn is also being seen as a massive gamble because Mr Salmond and the Nationalists are viewed in Scotland as a popular and competent government while Labour and Ms Alexander are going backwards in terms of their appeal among Scottish voters.

Recent polls give mixed signals as to the result of a referendum. When Scots are asked whether they want to see the UK broken up, they reject independence decisively. Last week such a poll put support for independence at its lowest level — 19 per cent.

However, when Scots are asked the more positive question — whether they want to see the Scottish government negotiating a settlement which would lead to the creation of an independent Scotland, it attracts much more support — 43 per cent in one recent poll.

Annabel Goldie, leader of the Scottish Tories, said Labour was guilty of a “betrayal” and was pandering to Mr Salmond. She added: “These developments are the final proof that Labour cannot be trusted with devolution.”

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