Joanna Cherry has confirmed she will step down from Westminster if she is elected to Ruth Davidson's Holyrood seat.
The SNP's Edinburgh South West MP said on Saturday she would seek support from her party to challenge for the Edinburgh Central constituency.
Angus Robertson has already announced plans to bid for the seat.
Ms Cherry confirmed on Sunday she would step down as an MP if she succeeded in being elected to Holyrood.
She said: "Edinburgh Central is my home branch, I have been a member there since 2008.
"I have lived in the constituency since 2002 and since 2015 I have been the MP for Edinburgh South West which covers a significant part of the Central seat, including Gorgie, Dalry Haymarket, Fountainbridge and part of Tollcross/Bruntsfield.
"I am very grateful to all the people who have approached me and encouraged me to put my hat in the ring when nominations open."
She added in a social media post: "This will be a contest about ideas and policies not personalities."
Mr Robertson, the SNP's former Westminster leader, revealed on Tuesday that he would be seeking the SNP's nomination to stand.
The Tories currently have a 610-vote majority in the constituency.
The seat was won from the SNP by the former Scottish Conservative leader at the last Scottish Parliament election in 2016 but Ms Davidson has indicated she will be stepping down at the next poll in May 2021.
Mr Robertson lost his Westminster seat to the Conservatives' Douglas Ross at the 2017 general election.
My statement on seeking to be @theSNP candidate for #EdinburghCentral in 2021 Scottish election. If I win the nomination & election to Holyrood I would stand down as an MP to focus on Scotland. This will be a contest about ideas & policies not personalities pic.twitter.com/COV42VKCRc— Joanna Cherry QC (@joannaccherry) February 23, 2020
Ms Cherry recently gained recognition for leading the Scottish court case challenging the five-week prorogation of parliament.
It was ultimately successful in the Supreme Court, resulting in the quashing of the suspension, which had been imposed in September.
Announcing his intention to contest the seat, Mr Robertson accused Ms Davidson of putting "other career interests in London ahead of the people she still represents at Holyrood" and argued that constituents "deserve better".
He said: "Edinburgh Central deserves a full-time MSP who will put the interests of their constituents first."