SCOTTISH Labour rebels are ready to trigger a leadership challenge against Richard Leonard, it has been reported.

Disgruntled MSPs believe they now have sufficient support to force a contest, but have sought clarification from party chiefs.

Last week, four Labour MSPs – James Kelly, Jenny Marra, Daniel Johnson and Mark Griffin – and four party peers called on Leonard to step down ahead of next year’s Holyrood elections.

The group now say they have a fifth Holyrood representative willing to join the cabal, which they insist is enough to spark a leadership challenge. According to their interpretation of the rules, just a fifth of the party’s 23 MSPs need to sign up.

It is not yet known who the fifth MSP is.

The Scottish Labour leader, however, insists no such mechanism exists.

Rebels Kelly and Johnson have written to party general secretary Michael Sharpe to seek clarity.

READ MORE: Richard Leonard missing from Scottish Labour meeting after efforts to oust him

The letter, seen by the Daily Record, reads: “We are writing to you as we feel there is an urgent need to clarify the rules of the Labour Party. In particular with regard to the procedure to challenge a sitting leader of the Scottish Labour Party.

“As you may be aware, in recent days it has been briefed to the media and stated publicly by Richard Leonard that there is no mechanism by which the Leader of the Scottish Labour Party can be formally challenged. However, we believe this is an inaccurate interpretation of the rules.

“The precedent has been set by the Labour Party that a leader can be challenged with the backing of 20% of the Parliamentary party and our understanding of the Scottish Labour Party and Labour Party Rule books confirm that this is the case.”

They added: “On this basis, our understanding is that five signatures is sufficient to initiate a challenge. We have five members willing to sign such a challenge. We therefore request clarification on this matter at the earliest opportunity.”

Leonard is under pressure to quit as polls show his party is on course for another dismal election performance in 2021.

A recent survey showed the former heavyweight of Scottish politics is on track to win just 14% of votes.

READ MORE: Richard Leonard could be 'ousted in days’ by Scottish Labour

Kelly and Johnson pleaded with their party leader to stand down, writing: “We reject the implication that, once installed, the leader of the Scottish Labour Party enjoys indefinite tenure. This is not democratic and goes against our party’s fundamental principles and values. This action has been driven by sorrow, not anger, after Richard Leonard has failed to command the support of MSPs, Labour activists and most importantly, the Scottish people.

“We are pleading with Richard, once again, to put our party first and to stand aside so that we can start the urgent work to regain the trust of the Scottish people ahead of next year’s election under a new leader.”

Earlier, it was revealed Leonard skipped a meeting of Labour MSPs today.

He had been due to give a leader’s report on the events of the past week, when the cabal launched its bid to oust him, but joined UK Labour’s NEC meeting online instead.