Lib Dems ready to back vote on split from UK

The Scotsman has learned that party strategists are now in serious talks about supporting an independence referendum in 2010 as they believe this could be the best chance of winning the argument and maintaining the union.

Senior figures are concerned that the SNP will increase their majority in Holyrood after the next Scottish Parliament election. Such an increase could give crucial momentum for an independence vote.

The referendum bill is due to be published on St Andrew's Day, but at this stage all the main opposition parties have said they will vote against it. This, for now, will block a public vote.

But if the Lib Dems, who have 16 MSPs at Holyrood, change their minds, this would bring the SNP within touching distance of securing a referendum.

A party source said: "There is serious consideration being given to it. The fact is, by 2011, the SNP could be governing with a majority. Labour, having lost the general election, will still be tearing itself apart and in no way to fight for the union.

"David Cameron would have imposed cuts on Scotland and there is a risk that more people will be motivated to support independence."

The source added that the debate was still continuing but that "policies can be changed".

Other Lib Dems, including MEP George Lyon and prospective candidate for Edinburgh North and Leith, Kevin Lang, have already called for the party to support a referendum and challenge the SNP immediately.

The news came as the party's Treasury spokesman, Vince Cable, used a keynote speech to warn of a "major constitutional crisis" under an incoming Tory government which could lead to the break-up of the UK.

He predicted that the Scottish Government could find itself on a "collision course" with a Westminster government led by David Cameron that had no Scottish mandate. Such a scenario was likely within two years, and unless action was taken it could lead to conflict and even Scottish secession, he said.

This was because the Tories, while possibly having "one or two" Scottish MPs, would have no support north of the Border. Such a scenario would be a "terrible tragedy" for Britain because the UK was "one of the great creations of this country", he said.

Only the Liberal Democrats, with their federalist policies of greater devolution, could prevent the looming crisis, he said.

Speaking at a fringe event at the party's conference in Bournemouth, Mr Cable highlighted the "unfinished consequences of Britain's devolutionary settlement."

He said: "I think that within a year's time, maybe two year's time, there will be a major constitutional crisis in Britain.

Mr Cable added there was a "looming scenario" where "you have a nationalist government in Edinburgh on collision course with a government in London that is not interested, actually would probably quite like to get rid of all those Labour MPs north of the Border, and the whole future of the UK will come into question".

He added: "I believe that would be a terrible tragedy because the United Kingdom is one of the great creations of this country – Britain, and something we should be proud of.

"Unless we grasp this, the situation is allowed to drift, it's going to lead to conflict and possibly secession. That is probably the most important constitutional issue we are going to face."

His words will carry extra weight as Mr Cable started his political life in Glasgow, where he served as a councillor.

Alastair Carmichael, the Liberal Democrat's Scottish affairs spokesman, backed Mr Cable's warning. He said: "Vince is quite right to highlight the dangers that could be posed by having a Scottish nationalist government in Edinburgh, while in London we will have a Conservative government which is effectively an English nationalist government."

But the Lib Dem's claims that the Tories would support independence through the back door were rejected by shadow Scottish secretary David Mundell. He said: "Vince Cable might like to tell people that he predicted the credit crunch, but his clairvoyant powers are well off the mark this time.

"If the Conservatives were to become the next UK government, then that would be because we had won the majority of UK seats.

"Scotland already has a devolved government to take account of its particular needs and we've set out how a Conservative UK government would foster a relationship of mutual respect with that. As for constitutional change, Mr Cable should know that the Conservatives are signed up to the exact same consensus as his own party, namely the Calman Commission."

A spokesman for Michael Russell, minister for the constitution, said: "What the Scottish Government propose – and what Vince Cable's party should support – is a free and fair referendum so that the people can choose Scotland's future in a democratic vote. We seek a new relationship of equality with our friends and neighbours south of the Border within a new social union including the Queen as our shared head of state.

"It is surely ridiculous that Vince Cable should be speculating about Scottish independence, while Tavish Scott is not even prepared to put the Lib Dems' preferred constitutional policy to the vote."

Meanwhile, Scottish Secretary Jim Murphy has also challenged Mr Salmond to go head-to-head in a debate.

In his letter he told Mr Salmond that the conference – Scotland: The Possible Future – presented a "good opportunity" for them to debate the issues facing the country.

But a spokesman for the First Minister said Mr Salmond would reject the invitation.

"This is another cack handed attempt by Jim Murphy to draw attention to himself and sideline Iain Gray, who is supposed to be the Labour leader in Scotland," he said.