SCOTLAND’S top prosecutor is to be questioned by MSPs  over his role in the Alex Salmond inquiry after the former First Minister’s evidence was censored on his department's advice.

Labour and the Tories had demanded the Lord Advocate, James Wolffe QC, appear at Holyrood today to explain why the Crown Office dramatically intervened in the parliament’s affairs amid claims of a "cover up". 

Labour secured an urgent question to the Government asking whether the Lord Advocate had been personally consulted about the intervention.

He is now expected to appear at Holyrood at 3.50pm.

Labour said Holyrood’s credibility now “hangs in the balance”, while the Tories accused the Crown Office of "strong-arming Parliament and suppressing evidence" in a bid to protect the First Minister.

Mr Salmond lawyers have also written to the Lord Advocate demanding answers about the Crown Office’s “unprecedented and highly irregular actions”. 

Mr Salmond has said Mr Wolffe is “manifestly conflicted” as both a member of the Government appointed by Nicola Sturgeon and head of the service which has now intervened over evidence directly relating to her honesty.

Mr Salmond's lawyers have asked Mr Wolffe to explain why the Crown Office only intervened this week despite knowing what Mr Salmond had written since January 15.

They have demanded the Crown Office preserve "all material and communications with all or any third parties which led to their decision to intervene", as this would show if they were leaned on to change their position.

READ MORE: Alex Salmond claims Nicola Sturgeon's husband part of plot to 'imprison me'

The developments come as the simmering row over evidence being denied to the Salmond inquiry threatens to become a full-blown parliamentary crisis.

On Monday evening, the parliament published a submission from Mr Salmond in which he accused Ms Sturgeon of repeatedly misleading MSPs and breaking the ministerial code.

If true, it would be considered a resignation issue for Ms Sturgeon, who denies wrongdoing.

Publication was approved by Holyrood’s cross-party management group, the Scottish Parliamentary Corporate Body (SPCB), which is chaired by Presiding Officer Ken Macintosh and contains one MSP from each party.

However the Crown Office, which is heavily criticised in parts of Mr Salmond’s evidence, said it had “grave concerns” that some of the material could breach a court order related to his criminal trial last year.

Despite having already published this evidence, and it being available elsewhere in the public domain, the SPCB then changed its mind yesterday, took down the evidence from the parliament’s website, and republished it with five of its 33 sections removed.

The parliament admitted the SPCB had “agreed to republish the submission in redacted form in line with representations from the Crown Office”. 

The changes mean the deleted material will not appear in the inquiery's final report and cannot be used as the basis to question Ms Sturgeon or other witnesses.

In his evidence, Mr Salmond accused the Crown Office of being too close to what he called a concerted and malicious effort to ruin him and even have him jailed.

He said the Crown Office was withholding vital evidence which would support his claims of a high-level SNP plot to remove him from public life, which included the participation of Ms Sturgeon's husband, and that under Mr Wolffe’s leadership it was “not fit for purpose”.

Labour MSP Neil Findlay raised the controversy in the Holyrood chamber, calling it a “crisis of credibility” for the parliament, while Tory MSP Adam Tomkins said the parliament had made a “shameful, historic error” in folding to the Crown Office.

Mr Salmond, who had been due to give evidence under oath today, last night pulled out of his appearance and has said he may now appear on Friday, subject to legal advice.

READ MORE: Alex Salmond pulls out of Holyrood inquiry after evidence censored

The inquiry is looking at how the Scottish Government bungled a probe into sexual misconduct claims made against Mr Salmond in 2018.

He had the exercise set aside in a judicial review, showing it was “tainted by apparent bias”, a Government flaw that left taxpayers with a £512,000 bill for his costs.

He was later charged with sexual assault but cleared of all counts at a High Court trial last March.

He has claimed the prosecution was driven by people close to Ms Sturgeon who resented his victory in the civil case and wanted to damage him and remove from public life, "even to the extent of having me imprisoned".

He said SNP chief executive Peter Murrell, Ms Sturgeon's husband since 2010, was among the plotters.

Labour MSP Jackie Baillie, who sits on the Salmond inquiry, said Mr Wolffe must come before parliament this afternoon and explain himself.

She said: “The credibility of the inquiry into the Scottish Government’s handling of harassment complaints, and indeed the credibility of the entire Parliament, hangs in the balance.

“The Crown Office’s unprecedented intervention yesterday demands explanation – we cannot have this Parliament cowed into submission by the will of the Crown Office.

“The Lord Advocate must appear before the Parliament to explain the actions of the Crown Office immediately.”

Scottish Tory leader Douglas Ross said: “The SNP Government and the Crown Office are shutting down scrutiny at every turn.

“The Lord Advocate must face Parliament to explain why the Crown Office are strong arming Parliament and suppressing evidence - not to protect victims’ identities - but to protect Nicola Sturgeon.

“The First Minister broke cover this week in a panic to demand Alex Salmond bring forward his evidence, only for the Crown Office to shut it down.

“If she won’t release her own evidence on Ministerial Code breaches, she’s a hypocrite and once again, she’s trying to dodge scrutiny.  

“The burden of proof is on the First Minister. However much she protests and tries to deflect, this inquiry is about her government and the Ministerial Code investigation is on her actions.

“This looks more and more like a cover up every day. Our Parliament is in crisis because of the secrecy and sleaze running throughout the ruling party of government.”

READ MORE: MSP warns Holyrood suffering 'crisis of credibility' over censored Salmond evidence

A spokesperson for Mr Salmond said: “Mr Salmond has never refused to give evidence and remains happy to do so.

"On Monday, he had confirmed attendance at the Parliamentary Committee today to deliver his evidence. His submissions had been approved and were published that day.

"Logistical and health and safety arrangements had been made for the evidence session and travel plans had been organised.

"On Monday afternoon the First Minister pre-emptively announced that there was no evidence of wrongdoing on her government’s part. This was before Mr Salmond’s evidence was even published.

"Then late on Monday night, after publication on the Parliamentary website the Crown Office intervened, which led to redaction of substantial sections of some of the very evidence the First Minister claimed did not exist.

"In light of this astonishing decision to intervene at the eleventh hour and in light of the timing, Mr Salmond asked the Committee to defer his evidence by 48 hours to enable his legal team to consider the full implications of this extraordinary intervention.

"Mr Salmond has now asked his lawyers, Levy & McRae, to write to the Lord Advocate as the Head of the Crown Office to ask for an explanation for the Crown’s unprecedented and highly irregular actions."