ALEX Salmond has denied claims that the Scottish Government is drawing up a report calculating the start-up costs of an independent Scotland.

However he confirmed he has held a meeting with an academic whose estimate of about £250m he has endorsed.

Speaking during First Minister's Questions, Mr Salmond dismissed as "nonsense" claims in a newspaper that a report was being rushed out.

However he said he and government officials had met Professor Patrick Dunleavy, of the London School of Economics, to discuss the academic's work.

Last month the expert dismissed UK Treasury claims, based on his own research, that it could cost up to £2.7billion to create a range of new institutions such as a ministry of defence, foreign office and benefits and pensions department.

A leaked cabinet briefing from 2012 revealed that work on start-up of costs of an independent Scotland was being carried out.

Since then, however, ministers have insisted it would be impossible to calculate a figure because much of the infrastructure required to run the country would be subject of negotiations.

Scots Tory leader Ruth Davidson said: "For Alex Salmond to continue hawking around his version of independence, while refusing to say how much it's going to cost, is nothing but an attempt to con people.

"How can people believe Alex Salmond's claims on the economy of an independent Scotland in 2020 when he can't tell them the set up costs in 2016?"

Liberal Democrat leader Willie Rennie said the "First Minister still doesn't have a clue about set-up costs" if there is a Yes vote in September.

Mr Salmond claimed the "unionist cabal" were trying to "exaggerate the costs of an independent Scotland".