ALEX Salmond's claim that Scotland is on the cusp of a second oil boom has been thrown into doubt by a new report.

The First Minister's claim "is not readily supported by the evidence", warns the Centre for Public Policy for Regions (CPPR).

In analysis based on the latest oil forecasts, the think-tank warns Scotland will plunge deeper into the red than the rest of the UK this year.

Finance Secretary John Swinney insisted Scotland would remain better off than the rest of the UK.

Alistair Darling, head of the Better Together campaign, said the Glasgow University-based body's study was "devastating" for the SNP.

It came as Business Secretary Vince Cable said the Coalition aimed to make the North Sea oil and gas industry a success story like the car industry.

The First Minister stated Scotland was moving into a second oil boom after his government produced forecasts for North Sea revenues which were more optimistic than figures used in UK Budget calculations.

However, today's CPPR report states: "Even if North Sea revenues turn out towards the top of the range projected in the Scottish Government's Oil and Gas Analytical Bulletin, it would not mean a return to anything like the level of revenues seen in the early 1980s. To suggest some sort of new oil tax revenue boom is about to emerge is not readily supported by the evidence."

Mr Darling said: "This is devastating for the nationalists. Betting a country's economic future on such a volatile and declining resource isn't credible."

The CPPR based its analysis on new oil forecasts by the independent Office for Budget Responsibility (OBR), which predicted a 40% drop in North Sea revenues this year followed by further falls up to 2018.

The think-tank also considered the Scottish Government's range of predictions for revenues over the same period.

The body says public spending will outstrip taxes raised in Scotland – including North Sea revenues – by £11.5 billion, or 7.5% of gross domestic product (GDP), in the current financial year. The UK as a whole will be in deficit by £114.5bn, or 7.4% of GDP, the report says.

It says Scotland's finances will be in worse shape than the rest of the UK's up to 2017/18, the period of the forecasts, based on the OBR's figures.

Scotland will remain relatively better off than the UK through to 2017/18 if the highest of the Scottish Government's four estimates for oil revenues proves correct. However, less optimistic estimates would see the advantage disappearing after 2014/15.

The CPPR report also reveals the extent to which an independent Scotland would be reliant on oil.

Stripping out oil to show the country's "mainland" balance sheet, Scotland would be £17.6bn in the red this year, or 14% of GDP.

The UK as a whole would be £121bn in the red, or 8% of GDP, says the report.

Co-author, economist John McLaren said: "Scotland's mainland fiscal balance ... is heavily in deficit, both in absolute terms and relative to the UK's.

"This position improves considerably once a geographic share of North Sea revenues is added in. As the Scottish Government's Fiscal Commission pointed out ... the objective should be to achieve as close to an overall onshore budget balance as possible."

Mr Cable said the launch of a new oil and gas strategy in Aberdeen on Thursday would focus on improving the fuel network across Britain.