RICHARD Leonard is facing a growing revolt after a fourth Labour MSP has asked him to stand down amid an increasingly bitter civil war.

Mark Griffin resigned as social security spokesperson this afternoon after informing the Scottish Labour leader he no longer has confidence in him.

"Your personal approval ratings are extremely concerning; less than half of the voting public know who you are, a majority of those who do have a negative opinion of your leadership and a majority of Scottish Labour voters have a negative opinion of your leadership," he told Leonard in his resignation letter.

READ MORE: Richard Leonard faces coup as MSPs plot to oust him

Leonard, leader for nearly three years, is under pressure to quit following a succession of dismal election results, poor polling figures for the party and dire personal approval ratings.

Griffin, an MSP for Central Scotland, is the latest colleague to call for Leonard to quit.

In his letter to Leonard, obtained by the Record, he said: “I had not planned on making any public intervention but feel compelled to, given the response to colleagues who have expressed their feelings on your leadership.

“You have labelled colleagues as disgruntled and factional for expressing opinions honestly and acting out of deep concern for the future of the Scottish Labour Party, and our ability to effectively represent the communities who depend on us.”

He continued: “We cannot hope to improve when any criticism, public or private, is dismissed as factional. I have had grave concerns about the future of the Scottish Labour Party for some time, especially following the disastrous European and General Election results.”

The National:

He concluded: “I do not have confidence in your ability, after three years in post, to turn the situation around. I hope you will consider resigning from your position as leader in the best interests of the Scottish Labour Party.”

Griffin’s call came after MSP James Kelly resigned as justice spokesman yesterday over Leonard's leadership.

And in a newspaper interview published today Labour MSP Jenny Marra also called for Leonard to go.

Their views were backed by fellow MSP Daniel Johnson this morning.

Leonard has refused to go and has threatened the rebels with de-selection.

Rhoda Grant, a fellow Labour MSP, has tried to rally the party behind the embattled leader.