London: Prime Minister Gordon Brown was trying to reassert his authority in a chaotic row over Scottish independence yesterday.

Labour's leader in Scotland, Wendy Alexander, was under pressure to back away from supporting a referendum on the future of the 300-year-old Union with Britain.

Her apparent breach of the party line left Labour's policy in disarray and gave the damaging impression that the Prime Minister's authority in his homeland was crumbling.

Nationalists applaud

Scottish Nationalist leader Alex Salmond gleefully claimed a victory saying the row had brought independence closer.

"The only consistent theme is that the Labour Party of Scotland now seem to be in support of a referendum bill - now that's a valuable concession," he said.

In a letter to Conservative leader David Cameron, Brown insisted Alexander was not calling for an immediate referendum.

"Wendy Alexander and I agreed that all parties in favour of the Union have a duty to expose the hollowness of the Scottish National Party's position: claiming they favour independence, yet wanting to postpone any referendum," he said.

His comments implied Alexander's call for a vote was no more than a tactical bid to embarrass Salmond, who is delaying a referendum until after the general election, when Labour may be weaker.

Yesterday Cameron challenged the Prime Minister to back or sack Alexander.

But, to the astonishment of the opposition, Brown denied she had ever called for a referendum, saying: "That is not what she has said."