The entire revenue of NHS Scotland could be wiped out if an independent Scotland makes a mistake with its oil revenue predictions, MSPs have heard.
The Scottish economy would be largely dependent on a volatile resource if it left the UK, according to opposition parties. Scotland may be unable to create a Norway-style oil fund without Norwegian levels of general taxation, Liberal Democrat leader Willie Rennie suggested.
The Scottish Government wants to siphon off oil revenues for use against future budgets, similar to Norway, which has gathered "a £400 billion" oil fund over more than two decades. But even with record oil revenues this year, Scotland is running a net fiscal deficit of £7.5 billion, according to opposition parties.
They questioned how Scotland could save for the future when oil would be needed to "plug the gaps" in the budget. Finance Secretary John Swinney insisted that Scotland is in "a relatively stronger position" than the UK, generating an extra £4.4 billion that it could spend as it wished under independence.
"If we're going to talk about Norway, lets talk about the fact that Norway has got a £400 billion oil fund which is being used to safeguard and anchor the Norwegian economy. Where is the oil fund for Scotland after 40 years of fiscal mismanagement by the UK?" he said.
"The UK Government has happily squandered oil and gas reserves propping up the UK economy but we have not seen in Scotland the ability to utilise these revenues in the way that our Norwegian friends have in terms of strengthening our economic future.
"The finances of the UK and Scotland were both in deficit last year, as were the finances of most members of the OECD. However, Scotland continued to be in a relatively stronger position as the UK as a whole, to the tune of £4.4 billion equivalent to £824 for every person in Scotland.
"A £1.4 billion boost to capital investment could have supported 20,000 jobs. We could have invested £1.4 billion in an oil stabilisation fund, as recommended by the Fiscal Commission to smooth any changes in tax revenues in future years, and we would still have been able to borrow £1.4 billion less than the UK in relative terms, thereby reducing our interest payments. But we only have the choice to do that if we are an independent Scotland."
Labour finance spokesman Ken Macintosh said: "I still entirely fail to see how we can save money that's a deficit. The First Minister has said Scotland would be better off by £800 but said we won't have the ability to invest or save that money. That's because it's a deficit not a surplus, and yet the SNP portrays it entirely the wrong way."
Scotland raised £45 billion from general taxation in 2010-11, compared with £94 billion in Norway which has a similar population. Scotland took £8 billion from oil revenues, compared with £39 billion from oil in Norway.