Nicola Sturgeon is facing calls to resign after fresh questions were raised about her role in the Alex Salmond affair.
The Scottish Government has published legal advice related to its botched investigation into allegations of sexual harassment against the former first minister.
It showed the government continued the legal fight despite being advised there was a “real risk” it would lose.
The failed action eventually cost taxpayers around £600,000.
Meanwhile, further witness statements released by a Holyrood inquiry have raised questions over Sturgeon’s version of events.
The First Minister is due to give evidence to MSPs on Wednesday, however the Scottish Tories said they would now submit a motion of no confidence her.
Scottish Conservative leader Douglas Ross said: “Credible witnesses have now backed up Alex Salmond’s claims and the legal advice shows the government knew months in advance that the judicial review was doomed but they still went on to waste more than £500,000 of taxpayers’ money.
“There is no longer any doubt that Nicola Sturgeon lied to the Scottish Parliament and broke the ministerial code on numerous counts.”
He added: “The weight of the evidence is overwhelming. Nicola Sturgeon must resign.
“We will be submitting a vote of no confidence in the First Minister.”
Responding to Conservatives’ statement, a spokesperson for the First Minister said: “The First Minister will address all of the issues raised – and much more besides – at the committee tomorrow, while the independent adviser on the ministerial code will report in due course.
“But to call a vote of no confidence in the middle of a pandemic, before hearing a single word of the First Minister’s evidence, is utterly irresponsible.
“It is for the public to decide who they want to govern Scotland and – while we continue to fight the Covid pandemic – with the election campaign starting in just 20 days, that is precisely what they will be able to do.”
The Scottish Government launched an investigation into allegations of sexual harassment by the former first minister, but it was found to be unlawful, unfair and “tainted by apparent bias” because of prior contact between the investigating officer and two of the women who complained.
Redacted legal advice published by the Scottish Government on Tuesday evening showed that lawyers advised them in September 2018 that there “is a real risk that the court may be persuaded by the petitioner’s case in respect of the ground of challenge based on ‘procedural unfairness’.”
On December 6, 2018 legal advisers told ministers that in their view the “least worst option” would be to concede the petition.
They wrote: “We understand how unpalatable that advice will be, and we do not tender it lightly.
“But we cannot let the respondents sail forth into January’s hearing without the now very real risks of doing so being crystal clear to all concerned.”
Deputy First Minister John Swinney said the published legal advice showed the Scottish Government were right to carry on with their legal action.
He said: “Today the Scottish Government has taken the exceptional step of releasing key legal advice.
“We have done this in recognition of the overwhelming public interest in rebutting the false allegations made about the advice informing decision-making in the judicial review.
“These documents are clear. Our legal advice was optimistic about the government’s prospects for success at the start. It became gradually but progressively less optimistic over time.
“It was only in December that the advice concluded that our case was no longer stateable and we should concede. Indeed, as late as December 11, ministers were advised that we should continue.
“Within a matter of days of being advised that the case was no stateable, we have taken the decision to concede. That was right and proper.
“Significantly, however, this comprehensively disproves claims that we had continued the case in defiance of legal advice. That is categorically untrue and these documents put that beyond doubt.”
Scottish Labour said the published legal advice showed the government’s handling of the complaints had been “indefensible”.
Deputy lead Jackie Bailie said: “The Scottish Government’s unlawful handling of harassment complaints appears to be indefensible, and I look forward to having the opportunity to question the First Minister on the failings of her government.”
Sturgeon has repeatedly denied breaching the ministerial code over the Salmond saga.