The SNP leadership race is being conducted “100%” properly, Deputy First Minister John Swinney has said.

Two of the three campaigns for the leadership – those of Kate Forbes and Ash Regan – have called for an independent audit of the vote to provide confidence to party members.

Mr Swinney, a former SNP leader who backs Humza Yousaf for the top job, said “I don’t know what all this is about”, after Ms Forbes’s campaign manager pushed for an independent body to be brought in “without delay” and a senior adviser to Ms Regan’s campaign said such a move would provide “reassurance” to party members and the public.

Michelle Thomson – who is running the Forbes campaign – said some concerns are “based on hearsay or are from bad faith actors”, but she added: “However, others are being openly expressed by individuals within the SNP of longstanding.”

Humza Yousaf, Kate Forbes and Ash Regan
All three candidates have called for the release of SNP membership figures (Jane Barlow/PA)

She argued that the fact questions are being asked at all “can only further undermine trust in SNP HQ”.

She added: “We all agree that the party must unify around any newly elected leader.

“I have asked that the SNP appoint a robust, experienced, third-party auditor of both the ballot processes and the eventual tally of the vote. This third party must have full oversight of all membership numbers, data and processes.

“This should be done without delay.”

Kirk Torrance, who is advising Ms Regan, said on Twitter: “Independent auditors will give reassurance to the SNP members and the general public that this ballot is conducted properly. This should have been the case from the outset.”

The election process is being carried out by Mi-Voice, an election services firm based in Southampton.

Ms Thomson said the SNP is “ultimately accountable and responsible for many of the processes, oversight and ultimate integrity of the ballot”.

Michelle Thomson
SNP MSP Michelle Thomson is managing Kate Forbes’s campaign (Fraser Bremner/Scottish Daily Mail/PA)

But speaking to BBC Radio Scotland on Thursday, Mr Swinney said: “I don’t understand half of these comments.

“The process is being conducted by an independent ballot services company, that is an independent organisation. They have got a professional reputation to deliver ballot services effectively and without question.

“My experience, and I have got a lot of experience of elections within the SNP. I have been a candidate in many of them, I ran many of them as the party secretary over many years.

“I have also seen this process we are going through just now operating in the election of previous deputy leaders of the party which we have undertaken in recent years and nobody, nobody, has raised an issue about the authority of those processes.

“They have been completely straightforward, efficient, independently organised processes, and this is exactly the same.

“So I don’t know what this is all about.”

Asked if he is satisfied the election is being conducted “entirely properly”, Mr Swinney said: “100%.”

It comes the day after pressure intensified on the party to release its membership numbers.

Previous estimates put the membership at 104,000 in December 2021, although reports suggest 78,000 online ballot papers have been sent out in the current leadership election.

All three candidates have called for the publication of the figures, with Ms Regan writing a letter to SNP chief executive Peter Murrell on behalf of herself and Ms Forbes saying the “information is crucial to fostering trust and confidence among the candidates, their campaign teams, and the party members who are participating in the election”.

Neil Gray, who is campaign manager for Mr Yousaf, said: “Humza’s campaign team also asked for the figures to be published and sought assurances this would be done as soon as possible.”

Reports suggest a meeting of the SNP’s ruling body will take place on Thursday to decide if the numbers should be published.

An SNP spokesman said on Wednesday: “Candidates have already been made aware that responsibility for the leadership election does not rest with any member of staff.”