Tommy Sheppard has announced he will stand for the role of deputy leader of the party.
The SNP MP for Edinburgh East said the party had to prepare for a second referendum on Scottish independence and still had “arguments to win”.
The current deputy leader, Stewart Hosie, has said he will step down in the autumn.
Mr Sheppard wrote in a blog: “We need to prepare for the challenges ahead, including IndyRef2 when it comes.
“That will be a far tougher test, and we need to be ready.”
Others to announce they are running are the party’s Westminster leader Angus Robertson and MEP Alyn Smith.
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