Nicola Sturgeon tonight backed the immediate transfer of all tax powers to Holyrood in a move that threatens a multi-billion pound cut to Scotland's budget. The First Minister was forced to admit her MPs would vote for fiscal autonomy as early as next year, despite the catastrophic collapse in North Sea oil revenues. Such a move would leave a massive £7.6billion black hole in Scotland's finances, triggering either higher taxes, deeper spending cuts or unsustainable borrowing levels. Nicola Sturgeon said she would back calls for all tax powers to be devolved to Scotland 'as soon as possible', but Labour leader Jim Murphy (right) warned this would leave a catastrophic hole in the country's budget . Miss Sturgeon struggled once again in a TV election clash screened by the BBC, just a day after she faced an audience backlash by refusing to rule out a snap second referendum on independence. She walked into a trap set by Labour leader Jim Murphy, who pointed out that one of the SNP's biggest supporters, billionaire Jim McColl, admitted Scotland is not ready for fiscal autonomy. But asked when she wants full tax powers, Miss Sturgeon said 'as soon as possible'. 'As Scotland's voice in the House of Commons, if the SNP is there in numbers we will be arguing for as many powers to come to Scotland as quickly as possible,' she said. 'I would like it as quickly as the other parties agree to give it.' Asked by Murphy 'would your MPs vote for it next year?', the First Minister replied: 'I would vote for it, would you support it?' To applause, the Labour leader swiftly responded: 'No I wouldn't. 'Absolutely not, and let me tell you why. This is the idea that we cut ourselves off from sources of taxation across the UK. Miss Sturgeon (centre) struggled slightly during a debate tonight in Aberdeen (pictured) just a day after she was booed for refusing to rule out another referendum after the election . Gaining full fiscal autonomy from the rest of the UK will likely leave Scotland with a £7.6billion shortfall in cash, according to independent experts, after the value of North Sea Oil plunged earlier this year . 'After the difficult time that Aberdeen and the north east of Scotland been through, the idea that we voluntarily give up the pooling and sharing of resources, the ability to transfer money across these islands - I don't think it makes sense.' The debate was held in Aberdeen University's Elphinstone Hall, and was chaired by the BBC's James Cook – who has been the victim of 'Cybernat' abuse in recent days. Miss Sturgeon, Mr Murphy, Tory leader Ruth Davidson and LibDem leader Willie Rennie – who all took part in an STV debate the previous night – were joined by UKIP's only elected politician in Scotland, MEP David Coburn, and Scottish Green co-convener Patrick Harvie. During the one-hour clash: . Much of the debate focused on the SNP's support for 'full fiscal autonomy', which former First Minister Alex Salmond has described as 'home rule' and critics have branded 'independence by the back door'. It would see the devolution of every tax – including North Sea oil revenues – and leave only defence and foreign affairs reserved to Westminster, ending the generous Barnett Formula that funds Scotland. Scottish Government official annual accounts show how Scots contributed £400 extra in taxes than the UK average last year, but received an additional £1,200 in public spending. Scots Lib Dem leader Willie Rennie (left) warned Miss Sturgeon against another referendum, while Scots Green Party Leader Patrick Harvie (right) called for an end to North Sea drilling . Last month, the highly-respected Institute for Fiscal Studies (IFS) predicted that a 'fiscally autonomous' Scotland would have a massive £7.6billion black hole in its finances. That is the difference between the estimated budget deficit for the entire UK in 2015-16 of 4 per cent of Gross Domestic Product (GDP) and Scotland's budget deficit of 8.6 per cent. According to the independent Office for Budget Responsibility (OBR), offshore revenues are expected to shrink to only £600million in 2016-17. That is a staggering 13 times smaller than the most optimistic figures Alex Salmond based his independence blueprint on. Speaking after the debate, Tory leader Ruth Davidson said Miss Sturgeon's election campaign is 'beginning to unravel'. One member of the audience warned the First Minister that she 'doesn't speak for everyone' in Scotland. In the earlier STV debate on Tuesday, Miss Sturgeon said next month's General Election is not a 're-run' of the referendum, but pointedly said 'that's another matter' when asked about her Holyrood manifesto for 2016. Her weak response was met with audible groans from the audience. Ruth Davidson (left), leader of the Scots Conservatives, said Miss Sturgeon's election campaign was unravelling. Ukip MEP David Coburn was branded a 'disgrace' by Nicola Sturgeon . During the show, the SNP leader insisted: 'I do accept the result of the referendum. There is a triple lock on this. 'Before it is inserted in the manifesto, public opinion has to change, and then people have to vote for the manifesto if it is in it, then people have to vote for independence.' Pressed on whether the Tories would block another referendum, Miss Davidson said: 'I do not see an area where if the circumstances arose again that we would. 'However, we would feel a betrayal very deeply when we were promised time after time by Nicola, by [Deputy First Minister] John Swinney, by all her MSPs, MPs, MEPs and councillors that this was 'once in a generation' and we were told by the end of the campaign it was 'once in a lifetime'.' Mr Murphy said: 'You don't get a mandate from an opinion poll, you get a mandate from a manifesto and you have gone from being a proud co-leader of the big Yes campaign to being the head of the 'maybes ayes, maybes naws' campaign.' Mr Rennie said: 'Just imagine if we had a different vote last September. 'I think there would be blind panic as a result of what has happened in the North Sea. 'Nicola Sturgeon has got a nerve to continue to argue for a policy that was soundly trounced in the referendum.' UKIP’S Scottish leader David Coburn was last night branded a ‘disgrace’ by Nicola Sturgeon for comparing one of her ministers to convicted terrorist Abu Hamza. The First Minister rounded on the MEP after the Scottish Daily Mail revealed how he made the comparison when referring to Muslim minister Humza Yousaf. Mr Coburn was also roundly booed by the audience in the BBC leaders’ debate as he claimed ‘open door immigration’ has contributed to the rise in food banks, and demanded a cut in foreign aid because most of it ‘goes to dictators’. In a fierce exchange, Labour leader Jim Murphy told him: 'Don’t demonise immigrants. How dare you?' Ruth Davidson . Best bit: A passionate defence of the UK, describing it as a ‘social union as well as a political union’. Key clash: A row with Nicola Sturgeon over a second independence referendum, in which she warned that breaking the SNP’s ‘once-in-a-generation’ promise would be a ‘betrayal’. Worst bit: Forced to concede that Westminster would not stand in the way of another referendum if the SNP wins a majority. Verdict: Not quite as sure-footed as she was in Tuesday’s STV debate, but her honesty with voters and passion for the Union shone through. 7/10 . Nicola Sturgeon . Best bit: Branded David Coburn a ‘disgrace’ to his face for comparing SNP minister Humza Yousaf to convicted terrorist Abu Hamza. Key clash: A battle with Jim Murphy over ‘full fiscal autonomy’ and what it would mean for Scotland’s budget. Worst bit: Admitted SNP MPs would vote for full tax powers as soon as next year – coinciding with a dramatic slump in North Sea oil revenues. Verdict: Unlike last week’s UK-wide debate, she struggled under scrutiny from her opponents, with full fiscal autonomy now a millstone around the SNP’s neck. 5/10 . Jim Murphy . Best bit: Vowed to fight to keep the Barnett Formula ‘today, tomorrow and forever’. Key clash: Took David Coburn to task for ‘demonising’ immigrants in an explosive confrontation that left the UKIP leader in pieces. Worst bit: Forced to admit that a Labour government would make ‘targeted’ cuts, less than 24 hours after he claimed the party may not make any spending cuts. Verdict: A commanding performance, forcing Nicola Sturgeon to sign up to massive budget cuts for Scotland. 8/10 . Willie Rennie . Best bit: Huge applause when he used self-deprecating humour to warn Nicola Sturgeon against ‘breaking a promise’ that last year’s referendum was a ‘once- in-a-generation’ vote. Key clash: Desperately tried to distance the LibDems from their coalition partners during exchanges with Ruth Davidson. Worst bit: Squirmed over the LibDems’ broken promise not to increase tuition fees south of the Border. Verdict: Came out fighting after failing to make any impact in Tuesday’s debate, and delivered the best joke of the night. 6/10 . Patrick Harvie . Best bit: Won applause for accusing UKIP of trying to ‘cancel our membership of the civilised world’. Key clash: Left looking foolish by presenter James Cook, when asked if opposing ‘capitalism’ would be a ‘red line’ for Green MPs. Worst bit: Telling an audience in Britain’s oil capital the country must ‘minimise extraction’ of North Sea reserves, jeopardising thousands of local jobs. Verdict: David Coburn saved him from making the most ridiculous comments of the night, but his arguments were at the level of a sixth form school debate. 2/10 . David Coburn . Best bit: Claimed Scotland would have called in the International Monetary Fund (IMF) by now if there had been a Yes vote in the referendum. Key clash: Clashed with every leader and the audience, and most of civilised society. Worst bit: Nearly every time he spoke. Booed for blaming immigration for the rise food banks and claiming foreign aid mainly goes to ‘dictators’. Verdict: Arguably should have lost his job weeks ago when he compared a Muslim minister to Abu Hamza. Added nothing to the debate. 0/10 .
Miss Sturgeon made the call in debate at King's College, Aberdeen, tonight .
Said she wants powers 'as quickly as the other parties agree to give them'
Scots Labour leader Jim Murphy said move would ruin country's finances .
Drop in value of North Sea oil would mean a £7.6bn hole in the budget .
Mr Rennie, who openly admitted the LibDems had broken a promise not to raise tuition fees, cautioned Miss Sturgeon against breaking her promise that last year's referendum was a 'once-in-a-generation' vote.
Miss Davidson was forced to accept the UK Government could not stand in the way of another referendum.
Mr Harvie called for the end of North Sea oil extraction – in a city where thousands of workers rely on its future.