SNP leadership: Regan and Forbes pen letter calling for vote clarity
Two SNP leadership candidates are demanding information from the party's chief executive to ensure a "fair and transparent" vote.
Ash Regan has published an open letter, also written on behalf of Kate Forbes, to Peter Murrell.
Mr Murrell, who is Nicola Sturgeon's husband, has been urged to clarify party member numbers.
The SNP told the BBC that responsibility for the election "did not rest with any member of staff".
The third candidate in the leadership contest, Health Secretary Humza Yousaf, was not mentioned in the letter.
However, SNP MSP Neil Gray said Mr Yousaf's campaign team had asked on Tuesday for the figures to be published and "sought assurances this would be done as soon as possible".
Following publication of the letter, Ms Regan demanded that the information be handed over by 15:00 on Thursday.
The letter states: "We request that you provide essential information pertaining to the current membership status and voting procedures within the SNP, which is necessary for ensuring a fair and transparent leadership election."
It calls for the SNP to reveal the number of "paid-up" party members, as well as the number of digital voting documents and postal voting papers issued to them.
The letter continues: "We have previously reached out to the National Secretary, Lorna Finn, with a request for this information.
"However, we have yet to receive a response, which has prompted us to address this matter through a formal open letter."
Ms Regan and Ms Forbes tell Mr Murrell it is his duty to ensure the voting system is "transparent, fair, and equitable".
Providing the requested information "as soon as possible" will ensure confidence in the process, the letter states.
"Your co-operation in this matter will not only demonstrate the SNP's commitment to democratic values and principles but also help maintain a strong and united party during this leadership contest," it adds.
A few hours after issuing the public letter, Ms Regan's adviser, Kirk Torrance, requested a "satisfactory response addressing our legitimate request for information" by 15:00 on Thursday.
If one was not received by that deadline then Ms Regan would hold a press conference outside the Scottish Parliament to "address this matter further."
Membership questions
A spokesperson for Kate Forbes said: "It is standard practice for any election to be made aware of voting numbers in advance. This should be no different."
After being contacted by the BBC, an SNP spokesperson said: "Candidates have already been made aware that responsibility for the leadership election does not rest with any member of staff."
The SNP has refused to confirm how many party members will be able to take part in the vote.
Westminster leader Stephen Flynn told BBC Scotland on Tuesday that he had "no idea" and that "I think the last time I heard it was about 100,000."
The SNP said its membership had reached 125,000 by 2019, but the Electoral Commission put the figure at 104,000 two years later.
The Mail on Sunday reported that Southampton-based polling firm Mi-Voice, which is overseeing the leadership vote, had been given the names of just 78,000 members by the SNP.
If this is correct, it would suggest that the party may have lost nearly 50,000 members over the past four years.
The newspaper also reported that Mi-Voice expected about 54,000 members to actually submit a vote.
Voting in the SNP leadership election, which is using the single transferable vote system, opened on Monday with the winner to be announced on 27 March.