But the ex-MP and MSP said that a snap poll – as proposed by Scotland's richest man Sir Tom Hunter – would be a mistake, insisting that there first needed to be a major UK-wide debate about the future of the Union.

His comments come as a new poll this weekend reveals 65% of voters in Scotland believe there should be a referendum vote within the next two years.

It follows Hunter's call for an immediate vote, revealed in Scotland on Sunday last week, in which he declared that Scots should get the chance to decide on the destiny of their country.

He said that Scotland would then be able to move on, either as an independent nation or as part of the Union.

The poll found that only 11% of Scots support Hunter's call for an immediate referendum. However, 28% think one should be held next year, with 26% saying it should be in 2010.

Only 21% think there should not be a referendum, with 15% expressing no view.

Following Hunter's call last week, several Labour MPs have declared they too want to force a referendum in a bid to "shoot the SNP's fox". The same poll this weekend shows that if a poll were to be held today, independence would be defeated. Only 34% of Scots would back independence, with 50% of Scots saying they oppose it.

McLeish told Scotland on Sunday: "I think the issue has to be resolved at some point with a referendum, but for that to happen there needs to be a more informed debate, and I think the public are both bemused and confused by so many conversations taking place.

"Yes, it has to be resolved at some point in the future, but to get there we need to take the public more seriously, we need to take the business community more seriously and we need to have a more informed debate that looks at the Union."

McLeish said that his favoured option was to turn Britain into a federal country, where Scotland and Wales would become semi-autonomous but would still be part of the UK when it came to defence and foreign affairs.

He attacked all the Scottish parties for failing to back it.

"I can't for the life of me see why some kind of federalism, with far more autonomy for Scotland, still part of the Union, can't be one of the options.

"A lot of people I speak to in Scotland, in all the parties including the SNP, see that as a valid option."

Gordon Brown is now coming under pressure from several Scottish MPs over the referendum question, but ministers are insisting they will not bend. Scottish Secretary Des Browne declares today that there is "no need" for a referendum when last year "two-thirds of electors in Scotland rejected the notion that our country should be broken up".

However, it is understood Hunter has received private backing for his own plan from across the political spectrum.

A spokesman for the billionaire said last night: "The political parties can't on the one hand claim voters don't want independence and then deny them the opportunity to vote on that very subject. There's no logic to their stance."

Hunter was backed by former Scottish Secretary Lord Forsyth last night. He said: "We should recognise the person Alex Salmond is – people voted for him because they were fed up with Labour, not because they wanted independence.

"We should end the instability and uncertainty, and get this argument out of the way. There's great anxiety in Scotland because of the uncertainty, and business hates uncertainty. I would support any proposal to have a referendum as soon as possible."

He added: "Alex Salmond has got his opponents in the Scottish Parliament dancing to his tune. He's the Pied Piper and he's going to lead them off the cliff. It's high time the Unionist parties stopped this nonsense from the Nationalists and said bring it (a referendum] on."

Commenting on McLeish's intervention, a spokesman for the First Minister said: "This is a positive contribution to the debate, and we particularly welcome support from Henry McLeish for a referendum. The leadership of the Labour and Tory parties are becoming more isolated by the day on this issue."

The poll, carried out by YouGov, took the views of 1,070 Scottish-based adults between April 2 and 4, 2008.