THE Scottish Government last night expressed confidence an independent Scotland would continue to enjoy the highest possible credit rating, despite new doubts.

A newspaper report claimed all three top ratings agencies – Moody's, Standard and Poor's, and Fitch – have indicated that an independent Scotland could not rely on automatically maintaining Britain's prized triple A rating.

If Scotland failed to achieve this rating, it would lose out on comparatively cheap borrowing costs.

The report was seized on by the UK Government as well as Labour, the Conservatives and the Liberal Democrats in Scotland as a warning that independence would carry a high price.

It was dismissed by the SNP Government, which said: "We are confident of Scotland having the top credit rating in common with other small nations such as Finland, Denmark, Norway and Luxembourg, and that position is supported by Scotland having stronger public finances than the UK as a whole and lower public sector debt."

All three ratings agencies declined to comment on specifics as they do not undertake unsolicited ratings and Holyrood has not sought a draft opinion.

One argument already posited is that an independent Scotland with large fiscal deficits, high public debt and reliance on the declining resource of North Sea oil and gas would inevitably lose its triple A rating.

This, in turn, would lead to higher borrowing costs and greater austerity as a new Scottish government sought to balance its books.

However, the SNP Government dismissed such a scenario. It said in the five years to 2009/10, Scotland was in a stronger financial position than the UK as a whole to the tune of £7.2 billion.

A spokesman said: "Scotland's public sector debt is lower than the UK's and lower than the EU and G7 average, confirming our underlying economic strength with independence. Scotland would be the sixth wealthiest country in the developed world in terms of GDP per head."

Yet Danny Alexander, the Chief Secretary to the Treasury, said: "Our fiscal and monetary alliance provides us all with deeper and more liquid markets, which facilitate access to capital markets for governments and businesses, helping us to reduce borrowing costs. The Scottish Government has to think carefully before sacrificing that stability through independence."

Johann Lamont, the Scottish Labour leader, said the claims meant the "economic case for separation is unravelling by the day". She said it was extraordinary the SNP had not approached them for a draft opinion.

"Basically, they are asking the people of Scotland to take a gamble on the economic future of the country," she argued.

Ms Lamont added: "While independence may be an article of blind faith for the SNP, people deserve to know the real consequences of breaking away from the rest of the United Kingdom.

"It would appear the consequences are more money would be spent on borrowing and less on school, hospitals and other public services."

Gavin Brown for the Scottish Conservatives said the reports were "deeply concerning".

He added: "A drop of just one notch would have severe consequences and it is vital that we maintain triple A status. If we are to present ourselves as a country worth investing in we must be seen as a solid economic prospect, and the rating the UK holds guarantees this."

Scottish Liberal Democrat leader Willie Rennie warned a drop in creditworthiness would hit every Scottish pocket.

He added: "The Scottish Government needs to not just assert there will be no problem under independence but it also needs to provide the evidence."