A senior Labour MSP yesterday signalled a significant shift in his party's position on an independence referendum, saying he was willing to discuss the matter with shadow cabinet colleagues.

Andy Kerr, the party's Shadow Public Services Secretary, spoke out as a former Labour minister said he believed they should "call Alex Salmond's bluff" by supporting a referendum.

Until now, Labour has dismissed the SNP's calls for a referendum and has joined the Conservatives and the Liberal Democrats to look at ways of winning more powers for the Scottish Parliament.

But writing in a Sunday newspaper, former enterprise minister Allan Wilson said Labour had allowed itself "to be sucked into a constitutional quagmire".

Instead, Mr Wilson argued, the party should "take on the Nationalists with their own ball" and support an independence referendum.

Mr Wilson, who lost his Cunninghame North seat in May, said there was "little doubt" that Scots would reject independence at the polls, allowing Labour to seize the political initiative.

He said: "Labour leader Wendy Alexander should call Alex Salmond's bluff and support an independence referendum and, in so doing, settle the constitutional debate and quash the economic uncertainty for at least 25 years."

Mr Wilson added: "There is little doubt unionists would win a referendum. And in so doing we would knock the wind out of the SNP's sails, plunging their party into a state of chaos."

Asked to respond on television, Mr Kerr said his former colleague had made "a decent argument" on a referendum.

He said: "I think what properly should happen is that we should have a discussion in the party. I would want to discuss that matter with other shadow cabinet colleagues."

Mr Kerr's remarks are in sharp contrast to Labour's official stance: the party has consistently ruled out any involvement in an independence referendum.

When First Minister Alex Salmond launched his "national conversation" white paper on Scotland's constitutional future, which included the option of a referendum, Labour's deputy leader Cathy Jamieson said: "No-one should be under any illusion, the white paper is about breaking up the UK, not making Scotland better."

Labour last night sought to play down Mr Kerr's comments, issuing a statement in his name which said a referendum was not "an immediate priority" for the party.

The SNP last night welcomed his and Mr Wilson's comments. Pointing to a YouGov poll in August which suggested that 74% of Scots back a referendum, Bruce Crawford, the Minister for Parliamentary Business, said Labour were "playing catch-up" with the rest of the country.

He said: "Finally, it appears the Labour Party has woken up to offering the people of Scotland what they want."