NICOLA Sturgeon has been called on to confirm or deny she knew her Chief of Staff had “interfered” in the complaints process against Alex Salmond several weeks before the First Minister said she had found out about the harassment claims against her predecessor.

In a Commons debate and using parliamentary privilege, David Davis, the former Brexit Secretary, said he had it “on good authority” that there existed from February 6 2018 an exchange of messages from civil servants suggesting that Liz Lloyd, Ms Sturgeon’s chief of staff, was “interfering in the complaints process”. He said one note pointed to the chief of staff’s “interference v bad”.

“If true,” he said, “this suggests the chief of staff had knowledge of the Salmond case in February not in April as she has claimed on oath. The FM also tied herself to that April date in both parliamentary and legal statements. She was, of course, aware earlier than that. The question is just how aware and how much earlier.”

Mr Davis told MPs how an anonymous whistleblower had backed up Mr Salmond’s claim of an SNP conspiracy against him.

The senior Conservative backbencher explained: “He or she starts their communication with the assertion that the evidence provided points to ‘collusion, perjury up to conspiracy.’”

He said the Scottish parliamentary committee appeared to have had some of the communication. “It was described anonymously by one of the committee members as ‘just private conversations that we have no business intruding on.’ Well, I will let the House be the judge of that,” insisted Mr Davis.

He said the texts would not provide conclusive proof of what the whistleblower described as a “’criminal conspiracy’” but, the Yorkshire MP argued, it did show “a very strong prima facie case which demands further serious investigation, by which I mean at the very least a thorough review of all the emails and all the electronic records for the relevant personnel at the relevant times.

“For example, these texts show there was a concerted effort by senior members of the SNP to encourage complaints. The messages suggest that SNP Chief Executive Peter Murrell co-ordinated [Sue]Ruddick[the party's Chief Operating Officer] and Ian McCann, the SNP’s Compliance Officer, in the handling of specific complainants.

“On September 28, a month after the police had started their investigation of the criminal case, McCann expressed great disappointment to Ruddick that someone who had promised to deliver five complainants to him by the end of the week had come up empty or ‘over-reached’ as he put it.”

Mr Davis said it was because of the failings of the committee not being able to hold the executive in Scotland to account that he had brought the debate before the Commons.

“We need to reinforce the ability of the Scottish Parliament to hold its own Government to account. I’m here to strengthen the Scottish Parliament not to bury it,” he declared.

The SNP and Ms Sturgeon have strongly denied that there was any conspiracy against Mr Salmond, describing it as a "heap of nonsense".

In 2019, the former First Minister stood trial and was acquitted in court of 13 sexual assault charges against him.

Last night, Douglas Ross, the Scottish Conservative leader, said: “If the First Minister’s side were aware of complaints against Alex Salmond in February 2018, an outrageous breach of those women’s privacy and confidentiality has occurred.

“February 2018 is also two months before Nicola Sturgeon originally claimed to find out about complaints. If her chief of staff knew then, and was interfering in the investigation, it blows another enormous hole in the First Minister’s story.”

The Moray MP went on: “If civil servants said the First Minister’s chief of staff was interfering in the investigation in a ‘very bad’ way, then that is a sacking offence. It raises serious questions about how she tried to interfere, how she found out, who told her, when she knew, and who she went on to tell.

“It further raises the question if anyone told Nicola Sturgeon that her chief of staff was interfering in the investigation. If they did, a number of lies have been told to the Scottish Parliament. If they didn’t, it still makes Nicola Sturgeon’s story of when she claims to have found out about complaints even more implausible.

“These are all ‘ifs’. We need Nicola Sturgeon to immediately confirm or deny these new allegations, and to agree to release the evidence that has been cited this week.”

A spokesman for Ms Sturgeon said: “As with Mr Salmond’s previous claims and cherry-picking of messages, the reality is very different...Every message involving SNP staff have been seen by the committee previously. Their views have been widely reported as dismissive of them.”