The deputy first minister had been preparing to face a no-confidence vote in Holyrood after the Scottish Government failed to publish its legal advice relating to Alex Salmond’s successful judicial review before a deadline set by the Scottish Conservatives.
The move comes as the Lord Advocate is set to give evidence in front of the Salmond inquiry later today following intense criticism around alleged political intervention in the publication of the former first minister’s submission on the potential ministerial code breach by Nicola Sturgeon.
James Wolffe QC and Crown Agent David Harvie will give evidence from 10am.
MSPs on the harassment complaints committee are also set to issue the committee’s third section 24 notice to Mr Salmond’s solicitors Levy and McRae.
This could see evidence disclosed to Mr Salmond during his criminal trial be made available to the committee, including potentially key evidence the former first minister said can prove the allegations of conspiracy against him.
Ahead of Ms Sturgeon’s appearance in front of the inquiry tomorrow, the Scottish Conservatives heaped pressure on the Scottish Government by submitting a motion of no confidence in the deputy first minister.
The move had been publicly backed by all opposition parties and independent MSP Andy Wightman ahead of a potential vote.
The Scottish Government had been defeated twice in two Holyrood votes last year calling for the advice to be released and the vote could have seen Mr Swinney lose his job.
However, the Scottish Government said it would now look to release the advice later today, meaning the motion is likely to be withdrawn by the Scottish Conservatives.
It is understood the move from the Tories, along with the extraordinary attacks on the judiciary by Alex Salmond and political opponents, forced the decision.
The deputy first minister went through the ministerial code process for releasing legal advice, with the decision to release it given the stamp of approval by law officers on Monday afternoon.
Responding to Mr Swinney’s decision, Scottish Conservative leader Douglas Ross said: “Despite two votes in the Scottish Parliament demanding the legal advice be published, John Swinney only backed down and U-turned to save his own skin.
"It's a pathetic reveal of what motivates the SNP. It's not about getting to the truth, it's only about self-preservation.
"But the Scottish Conservatives will not remove our no-confidence vote motion until the government guarantees it will fully publish the legal advice.”
Scottish Liberal Democrat leader Willie Rennie said: “The committee have already been offered a private viewing of the legal advice, but for it to be useful they need to be able to cite it and publish extracts in their report. Providing bits of the advice and only to the committee in private is no use whatsoever.”
Scottish Labour deputy leader and committee member Jackie Baillie said: “This screeching U-turn from John Swinney may well be a cynical move to save his job, but it is very welcome nonetheless.
“I would like to gently remind Mr Swinney that the Scottish Parliament twice voted for the government to hand over its legal advice. The committee particularly wants to see external counsel’s advice from when they were first engaged in August – and it must come without any redactions.”
Mr Swinney said: “In normal circumstances, government legal advice is not released. Indeed, such is the importance of being able to get frank, private advice, it is almost unheard of for the legal advice to be released.
“But we have to acknowledge that the issues at stake now are not normal. The very integrity of the legal system is being questioned.
“Serious allegations have been made. This material allows people to confirm that these allegations are false.
“We have already shared in private with the Scottish Parliament’s committee on these issues the substance of the advice.
“Now we recognise that in order to counter to the false claims being made by some, we must go further. Subject to the mandatory legal checks and processes, we will release the key legal advice.”
The move to publish the legal advice comes as Angus Robertson, an ally of Ms Sturgeon, accused opposition politicians and parts of the media of a “full-on Trumpist assault”.
In a column , he said: “Having failed to lay a glove on her, opposition politicians and the anti-SNP commentariat have launched a full-on Trumpist assault, deploying character assassination, the wildest exaggerations, accusations and conspiracy theories.
"Instead of a genuine interest in the female complainants who reported the behaviour of the former first minister, they have attacked his successor.
"Even a cursory glance at the social media timeline of Tory MSPs shows that this is about taking out Nicola Sturgeon rather than protecting women.”
Ms Sturgeon’s appearance in front of the inquiry has also been confirmed for 9am tomorrow in what is likely to be a marathon session.
The committee is examining the botched handling of harassment complaints against Mr Salmond by the Scottish Government, which led to a £500,000 legal bill after the Government conceded a judicial review challenge on grounds the process was “tainted by apparent bias”.
Mr Salmond was also acquitted of sexual offence charges in a trial last year.