SNP ministers swiftly decided to blame Westminster after learning within weeks of taking power that one of their biggest manifesto pledges was unaffordable.

Cabinet minutes reveal plans to use complaints about Treasury funding as "political cover".

The SNP manifesto of 2007 said it was "time to dump student debt" and promised an SNP government would prioritise "removing the burden of the debt repayments owed to the Student Loans Company by Scottish domiciled and resident graduates".

At the time, the quango had around £2 billion of Scottish student debt on its books, and just servicing the interest would cost the government at least £64 million a year.

On June 5, 2007, at just the third SNP Cabinet meeting, then Finance Secretary John Swinney presented a paper on the Scottish Government's forthcoming strategic spending review.

Due out in November, this would cover broad Holyrood spending plans from 2008/09 to 2010/11, effectively to the end of the SNP's first term, and likely UK Government funding.

Mr Swinney said there was not enough money to meet and maintain spending pressures inherited from the last government as well as the SNP's own manifesto commitments.

There would be a "potential budget shortfall of £5.2bn if no action was taken".

The Herald:

At the same Cabinet, Education Secretary Fiona Hyslop presented a paper on urgently delivering the SNP promise to abolish the graduate endowment form of tuition fee.

However, she conspicuously did not commit to "relieving the burden of debt", saying that would be fed into the spending review.

On July 10, Mr Swinney presented a follow-up which said it was clear that "some significant reprioritisation of spend will be required" given the "harsh reality" of the situation.

The Treasury was "taking a very hard line," he told the Cabinet, with a very tight settlement. He asked colleagues to decide which manifesto commitments to fund and which to drop.

According to the minutes, First Minister Alex Salmond told the Cabinet to bear in mind certain "political points", including stressing the "big picture" context "to ensure that responsibility was properly allocated to the Treasury if their inflexibility remained a serious problem".

On September 4, Mr Swinney presented another paper on the spending review which said Ms Hyslop's department was unable to fund the "removal of student debt burden", which "cannot be introduced for less than £64m per annum".

An annex to the paper included a note about the political consequences of breaking the promise on debt, including a possible backlash from the National Union of Students.

Under "manifesto commitments not being funded", it said: "Remove student debt burden". It also said: "NUS expecting this from 2008/09. Students continue to accrue debt. Open to criticism. Political consequences. Will fall behind England in grant support."

In discussion, ministers agreed the available funding meant "it would not be possible to make any progress on relieving the burden of student debt".

"While the need for engagement with the UK Government on debt relief provided a degree of political cover on that item, Cabinet would need to consider collectively the political ramifications … and the failure to deliver on key manifesto commitments."

Ministers also stressed the importance of blaming the previous Labour-Liberal Democrat administration and the UK Treasury. "It would be important to develop a strong political narrative which pointed clearly to substantial inherited pressures, and to the impact of a settlement determined at UK level. It was likely that the impact of a tight settlement at UK level would quickly become apparent, and the position on Scotland would be set helpfully against that backdrop."

In November, Mr Swinney also put blame on "insufficient parliamentary support" for the policy when he announced the U-turn to Holyrood.