Two more high-profile SNP MPs have ruled themselves out of the contest to be the party's new deputy leader.
Tommy Sheppard stood for the job last time, but said he was more "protagonist than referee".
The party's home affairs spokeswoman Johanna Cherry QC said she could better serve the independence cause in her current role.
So far, Glasgow MSP James Dornan and party activist Julie Hepburn are standing to succeed Angus Robertson.
He quit the role eight months after losing his seat in the 2017 general election.
MPs Pete Wishart and Ian Blackford, have already ruled themselves out for the post.
Ms Cherry said she had received support to stand, but has decided against it.
She tweeted: "Huge thanks to all across the indy movement who've asked me to stand for @theSNP depute leader.
"After long & careful consideration I've decided that, for now, I can best further the cause of independence in my current role."
Writing in the Sunday Herald, Mr Sheppard said the deputy role is more about how policy is made rather than its content.
He said: "I want to be to free to contribute and lead debates about the policy we should advocate and that's harder if you're running the policy-making machinery.
"And I think we've had some success here. On fracking, the National Investment Bank, and other policy areas we've seen grassroots policy working its way through branches and conference to end up as party and government policy.
"I intend to continue to work with others to similarly shape our future policy agenda."
Glasgow MSP James Dornan was the first to announce he was seeking the post, with Julie Hepburn announcing her bid in February
Ms Hepburn is not in elected office, but she is well known within the party and has worked for senior politicians.