Ian Blackford is stepping down as leader of the SNP’s Westminster leader after more than five years in the top job.
In a statement, the MP said it is time for “fresh leadership” in the party and pledged to fully support his successor.
The outgoing SNP House of Commons chief will formally decline to stand for reelection at the party’s Westminster annual general meeting next week.
It comes days after reports emerged MPs were plotting to oust him from the role.
Aberdeen MP Stephen Flynn was touted as a possible replacement, but denied interest in taking on the job.
Mr Blackford said: “After more than five years in the role, now is the right time for fresh leadership at Westminster as we head towards a general election and the next steps in winning Scotland’s independence.
“During my time as leader, the SNP won a landslide victory in the 2019 general election, with an increased share of the vote and MPs.”
The departing leader said he would stay on as Ross, Skye and Lochaber MP.
‘New role’
He added: “I have also accepted a new role at the centre of the SNP’s independence campaign, leading on business engagement.
“I would like to thank our MPs and staff for all their support over the past five years.
“Whoever replaces me as Westminster leader will have my full support as, together, we stand up for Scotland’s interests and democratic right to choose our future in an independence referendum.”
Mr Blackford first took on the leadership mantle when he succeeded Angus Robertson in 2017.
His leadership came under pressure earlier this year over his handling of sexual misconduct allegations against SNP MP Patrick Grady.
He was criticised not forcing Mr Grady to step down as the party’s chief whip when accusations against him first emerged.
‘Humiliation’
Scottish Labour MP Ian Murray said the SNP is in “total disarray”.
And Tory MSP Craig Hoy said: “Ian Blackford has jumped before he was pushed. His resignation is a total humiliation for Nicola Sturgeon.”
Nicola Sturgeon said: “I would like to pay tribute to Ian Blackford for his five years as leader of the SNP’s Westminster group.
“He led the group at a time of huge electoral success for the SNP.
“I would like to place on record my thanks for Ian’s diligence, tenacity, friendship and loyalty in his time as group leader.”
Ms Sturgeon also denied there had been a “coup” in the group.
“No, it’s not a coup,” she said.
“Ian has been Westminster group leader for five years now and he represents one of the furthest flung constituencies in the country.
“He’s making the decision given all that lies ahead for the SNP, given all the exciting work that lies ahead for the SNP, that this is the right decision for him to pass on the baton.