But the claims were rejected by Finance Secretary Derek Mackay who insisted that Scotland can longer afford to be part of the "failing" the UK.
Scotland's economic shortcomings were down to it's current situation as part of the union, the SNP minister added.
He faced claims today that he should be "embarrassed" about revised figures released last week which showed that £5 billion has been wiped off the value of the economy.
The revision, down to £175bn from £180bn, were thrown into focus during exchanges at Holyrood today as Nicola Sturgeon pushes forward fresh demands to hold a second independence referendum.
Tory finance spokesman Murdo Fraser said: "Scotland's notional deficit now stands at £12.6 billion, or 7.2% of GDP vs 1.1%, the highest in Europe and well above the EU maximum of 3%.
"An independent Scotland, which the cabinet Secretary referred to would face eye-watering austerity as a result. So, where would the cuts fall if he had its way?"
Over the past year Scottish growth was 0.6% compared with 1.3% UK wide.
But Mr Mackay insisted that there would have been quarters when Scottish growth was higher than UK Growth and ministers are investing in the economy.
"The unionist argument is failing so badly that you're now back to saying Scotland cannot afford to be an independent country," Mackay said.
"Scotland cannot afford to be part of this failing union."
He added: "Scotland's current estimated notional deficit is as a consequence of our current constitutional position, not what we could do with independence.
"Austerity is the price of the union not independence.
"We could of course grow our economy and spend more on public services if we had the levers of control that most normal nations have, rather than be bound by a migration policy that doesn't suit our economic needs in our country, just one example of where the business community agrees with this Government.
"So it is the case we could do much better with all the levers of independence so resisted by the Tories."
SNP ministers have come under fire for seeking to "hide" the report which was published last week, without notification to the media.
Liberal Democrat leader Willie Rennie said: "Surely he should show some scintilla of embarrassment that in the context of a debate about the constitution and about Brexit, that he is not open about these things.
"There should be a proper debate in that context so that we can all understand the state of Scotland's finances and what future we would like for our country.
"Is he not a little bit embarrassed about that?"
But the Finance Secretary rejected claims he sought to "bury" the figures.:
"These figures were published pro-actively - they were published as part of a published timescale and timetable of reports that followed from the UK's ONS that feeds into it," he said.
"These are facts this is true - these are independent statisticians who produce these stats. The problem is with opposition members who misinterpret them, trying to undermine the economic strength of their own country which I find embarrassing."