Plaid Cymru leader Leanne Wood has said she will not stand to become an MP in the Rhondda.
Ms Wood said she was "seriously considering" the move after a General Election was called for 8 June.
But on Sunday, she Tweeted: "After much consideration, I'm not standing as MP for the Rhondda. Confident that @Plaid_Cymru will have very strong candidate."
The seat is currently held by Labour's Chris Bryant.
Ms Wood took the Rhondda seat from Labour in the 2016 assembly election, beating former minister Leighton Andrews.
Speculation had been mounting she would throw her hat into the ring for the Westminster seat.
However, Ms Wood, who has been Plaid leader since 2012, distanced herself from the move while speaking on BBC Radio Wales' Sunday Supplement programme earlier on Sunday.
"On balance, I'm coming down against, as we've got other people who I believe can win in the Rhondda," she said.
"Going to Westminster, for me, would mean I couldn't be the leader of the party," she added.
"The National Assembly is an important institution to us a party. It is vital that the leader is in that institution."
'This is our chance'
Plaid currently has three MPs in Westminster and are targeting at least two more seats in the General Election.
Of Wales' 40 MPs, 25 are Labour but Ms Wood says they are in "no fit state" to provide an opposition to the Conservatives.
"There is a good opportunity for us in this election," she said.
"Labour are divided and seem unable, therefore, to protect people in Wales. We know that the Tories are a threat to our nation and a threat to our economy.
"There is an opportunity for Plaid Cymru to make sure Wales has a strong voice to defend Wales and the only way we can do that is to ensure we have a strong team of Plaid Cymru MPs in Westminster.
"This is our chance."