ALEX Salmond has sought to revitalise the campaign for independence by producing a new report claiming the North Sea will generate up to 82% more in tax revenues over the next six years than previously accepted figures indicate.

The Scottish Government's Oil and Gas Analytical Bulletin said reserves in Scottish waters could yield £57.1 billion between the current financial year and 2017/18.

The figure is dramatically higher than the £31.3bn forecast by the independent Office for Budget Responsibility (OBR) used in UK Budget calculations.

The new report – coming less than a week after a leaked briefing paper revealed concerns at the heart of the SNP administration over the state of the country's finances – was immediately dismissed by pro-UK parties.

But speaking during a visit to oil industry leaders in Aberdeen, the First Minister said: "There can be little doubt that Scotland is moving into a second oil boom.

"Even with a cautious estimate of prices remaining at $113 a barrel being used, it's clear that Scottish oil and gas could generate more revenues than has previously been assumed."

The new study looked at a range of scenarios based on increased North

Sea investment over the past 12 months and more optimistic estimates of future oil prices than the $92 per barrel figure used by the OBR.

Taking an average of the uprated figures, the Scottish Government said the Scottish North Sea sector would produce £48bn up to 2017/18, still 54% higher than the latest OBR forecast.

The UK's top oil economist, Professor Alex Kemp, of Aberdeen University, said: "The OBR has been pessimistic about production levels and pessimistic about oil price scenarios as well.

"In the medium term, what the Scottish Government has said is possible. I'm a little more cautious about the near-term figures."

He said he expected revenues for this year and next to be lower than predicted because oil companies will benefit from tax breaks for their huge investment in the North Sea.

The report brought a scathing response from the pro-UK parties, which last week accused the SNP of presenting an upbeat vision of independence at odds with ministers' private fears.

Alistair Darling, head of the Better Together campaign, said: "What is most alarming about today's announcement by the Nationalists is that they have traded the long-term future of our country for some short-term political headlines."

He added: "If the Nationalist figures are wrong – even by a relatively small amount – then they would be taking vast sums of money out of Scotland's budget. It would be our schools, our hospitals and our pensions that would suffer as a result."

Labour MSP Richard Baker said the SNP "have been embarrassed by what they agreed in private, so they manufacture figures to spout in public five days later." Scottish Conservative leader Ruth Davidson MSP accused the Scottish Government of rushing out "a radically brighter outlook", while the SNP's pro-independence allies the Scottish Greens accused ministers of "shameless hypocrisy" for basing their campaign on oil after setting ambitious climate change targets.