Nicola Sturgeon under fire as Scotland's debt set to hit record £50bn by 2020

Scottish Government has an annual budget of £30bn but this figure has been dwarfed as a result of a spending spree on schools, roads, railways, higher education and hospitals

Nicola Sturgeon and her deputy first minister and finance minister John Swinney (PA)

Nicola Sturgeon is facing calls for greater openness and scrutiny of the Scottish Government's public finances after an investigation found its mountain of debt is set to hit a record £50bn by the end of the decade.

Holyrood has an annual budget of £30bn but this figure has been dwarfed as a result of a spending spree on schools, roads, railways, higher education and hospitals - borrowing billions of pounds from pension funds, international banks and Treasury, according to the Guardian.

The revelations have led to calls by Caroline Gardiner, Scotland's auditor general, for greater transparency over public finances north of the border.

It comes as Scotland prepares to take over a whole new set of tax-raising powers as part of the Scotland Bill currently going through the Westminster Parliament.

John Swinney, the Scottish finance secretary, is also expected to announce spending cuts in the Scottish Government's Budget on Wednesday - following George Osborne's decision to cut Scotland's block grant by 1.3 per cent.

Ms Gardner said opening up its finances was a "basic matter of accountability" and was needed “to enable the Scottish parliament to make some of the difficult decisions that it will need to make in future, particularly as it takes on its new tax-raising powers.”

“It is critically important that the Scottish parliament and the people of Scotland have got a very clear picture of what both those assets and those long-term liabilities look like," Ms Gardner added.

The Scottish Government insisted it limited borrowing to 5 per cent of its day-to-day budgets and said ministers were “acutely aware of our responsibility to be transparent and accountable”.

Responding to Ms Gardner's demand for greater transparency, a spokeswoman for the Scottish Government said: “The Auditor General has suggested that the Scottish Government should produce a further set of consolidated accounts bringing together the devolved public sector in Scotland; that does not mean that the information is not currently available – each body produces its own set of annual accounts.”

“The Auditor General has suggested that the Scottish Government should produce a further set of consolidated accounts bringing together the devolved public sector in Scotland; that does not meant that the information is not currently available – each body produces its own set of annual accounts.”

The spokeswoman added: “Public sector debt and affordability are key responsibilities for all the public sector. The Scottish Government is committed to sustainable levels of public sector debt – our approach is to use revenue funded methods of investment at a sustainable level while not overly constraining our choices in future years."