The anti-independence lobby is losing the economic argument ahead of the 2014 referendum as two leading business figures add to the debate on independence, it has been claimed.

Comments from Clyde Blowers founder Jim McColl and entrepreneur Sir Tom Hunter come as a poll suggests a slightly improved picture for the Yes campaign for the first time in recent months despite a majority still backing the Union.

The latest poll showed a healthy 15-point lead for the No camp, by 47% to 32%, but those undecided on 20% would be sufficient to bridge the gap.

The results follow fresh views on the independence debate from Mr McColl and Sir Tom, who are known to be sceptical about the case for the Union.

Mr McColl, chairman and chief executive of Clyde Blowers, likened independence to a management buy-out from the UK. Sir Tom, the entrepreneur from a sports retail background, castigated the scaremongering of the Better Together campaign and blamed both sides for the "factual void" in the debate.

Following their remarks, SNP Westminster leader Angus Robertson MP said: "The anti-independence side is losing the economic argument as more and more people recognise the opportunities a Yes vote in next year's referendum offers Scotland.

"On the economy, as on a host of other issues, it is people in Scotland who are best-placed to make decisions over the direction Scotland takes, and only a Yes vote will give us the opportunity to shape policies that always put the needs of people living here first."

However, a spokesman for Better Together rejected accusations of negativity.

"We are clear there is a positive case to be made for staying in the UK and we have been making this case as we go round the country.

"But it's not negative to ask questions of people who are advocating something that could change our lives forever."

The latest research on voting intentions, conducted by Canadian-based pollsters Angus Reid, canvassed opinion from 1003 Scots.

When questioned about the financial impact of independence, 14% of those asked said they would be better off, 38% worse off, 27% said it would make no difference and 21% said they were not sure.

Mr McColl wrote in a newspaper article: "While Westminster policies may work for London, they are not working for Scotland, for our economy or our society.

"A different approach is needed if we are to make Scotland the kind of country we all know it can and should be.

"We have a Government responsible for economic policy whose focus is not growth in Scotland but rather London and the south-east of England. That tells me Scotland is a nation in desperate need of a well-planned and thought-through management buy-out."

Sir Tom, lamented the choice between a "leap in the dark or staying with a moribund status quo" and said: "Never, in my view, has such a factual void filled such an important debate."

He added: "The No campaigners are digging themselves one enormous hole if they believe a dual 'status quo' and 'scare them to death about independence' message will work."

But he was also critical of the Scottish Government, saying: "Alex Salmond, one of the most talented politicians of his generation, and his Cabinet must also move away from obfuscating the issues, the costs, the EU membership, and on to a clearly defined and costed programme for independence in 2014."

Yes Scotland welcomed the poll, saying: "This is a further indication there is solid and sustained support for a Yes vote in 2014 and with around one-fifth of voters yet to make up their minds there is everything to play for.

"It is also significant that the number of people who think they would be better off or no worse off in an independent Scotland is higher than those who think they would be worse off."