The leader of Scottish Labour is to face a vote of no confidence at a meeting of the party’s governing body.
A motion has been submitted to the party’s Scottish Executive Committee (SEC) asking it express that it has no confidence in Richard Leonard’s leadership.
The committee is expected to vote on the motion on Saturday morning.
Mr Leonard is already facing calls to quit from some of his own MSPs – but says he has no intention of doing so.
It is understood that the motion to the SEC has been signed by a third of its members – meaning it will go to a vote of the full committee.
The committee is made up elected representatives as well as trade union officials and representatives of the party’s grassroots membership.
Mr Leonard said that many of the SEC members who had signed the motion were “not mandated by their organisations to vote in that way”.
And he said the last thing Labour supporters and potential voters wanted to see was the party “turning in on itself”.
He said the move to oust him was “entirely factional”, adding: “They have nothing to say or offer, no ideas, no plan to protect jobs and living standards against the backdrop of the Covid crisis.”
It comes after four Scottish Labour MSPs – James Kelly, Daniel Johnson, Jenny Marra and Mark Griffin – publicly called for Mr Leonard to resign earlier this month.
They have claimed that the party faces “disaster” at next year’s Scottish Parliament election if he remains in his post.
Mr Leonard, who was a close ally of former UK Labour leader Jeremy Corbyn, still enjoys the support of many on the left of the party.
But his critics point to the party’s dismal opinion poll ratings as proof that change is needed.
Scottish Labour is currently the third largest in the Scottish Parliament, behind the SNP and Conservatives, and lost all but one of its MPs in last year’s general election.