With less than a year to go until Scotland votes on independence, the battle over whether the nation would win or lose economically from separation has begun in earnest with contradictory and confusing claims on both sides.

SNP first minister and head of the pro-independence movement, Alex Salmond, published the government's economics report setting out all the powers that would fall to an independent nation.

"Scotland can more than afford to be a successful independent country, with a thriving economy and opportunities for everyone," he said.

"Independence will give us the chance to build an economy that takes advantage of Scotland's unique strengths and size to deliver a more outward-focused, fairer and resilient economy, boosting revenues and creating many thousands more jobs."

But leader of the anti-independence Better Together campaign, Labour's Alistair Darling, claimed that a recent report by the Institute of Fiscal Studies showed that declining income from North Sea oil and an ageing population meant there would be a bleak future in store for an independent Scotland.

Deep spending cuts or increased taxes would be necessary to make the nation sustainable in the long-term, he claimed.

Darling said: "If we were to leave the UK we would face the prospect of big tax rises, damaging cuts to public services - or a combination of the two.

"The Nationalists have chosen to ignore reality and to offer up a type of fantasy economics that beggars belief."

The clash comes ahead of the publication of the Scottish government's White Paper, setting out in detail the benefits of independence.

But on current showing it seems likely the two campaigns will run into the danger of blinding voters with statistics and claims over economic benefits and setbacks that will mean little to them, even if they could determine which were most accurate.

It is expected that many voters will, in any case, vote more out of an instinctive, emotional feeling about whether they want to remain part of the Union or not, and it is those feelings that much of the campaign will address.

There was a taste of it when Labour's former first minister and member of the unionist campaign, Henry McLeish, said David Cameron's "rich, posh Tory" image would do great damage to the anti-independence campaign and he should keep his distance. Cameron was worth about five points to the "Yes" campaign, he suggested.

He told the Daily Telegraph: "It is an alien political culture that he is exuding. Because of the history of Scotland from Thatcher onwards, Scots mainly are very dismissive of Conservatism," he said.

"Cameron also brings that edge that even Thatcher didn't bring: the rich, posh image. Osborne is the same ... They also exude this political distance so much that I would expect for Scots that Cameron is a much scarier figure than Margaret Thatcher ever was.

"It is not an intellectual, logical [decision]. It is an instinctive, cultural, political reaction to a party that in many respects is widely despised in Scotland."

In fact there are clear signs that Cameron is well aware of the antipathy to him and his image and he has already decided not to present a high profile figure as part of the anti-independence campaign.

He has, for example, refused a head-to-head debate with Salmond, saying the right person to meet for such a clash is Darling.

It is also believed that, while Cameron will make the case whenever necessary, he will not be making prominent appearances in Scotland in the run-up to the vote.