Humza Yousaf is battling to save his position as First Minister after his former allies in the Scottish Greens vowed to vote against him in a motion of no confidence.

The SNP leader dramatically brought the powersharing deal with the Greens to an end but now faces a backlash which could cost him his job.

Allies of Mr Yousaf insisted he was “coming out fighting” in the face of a concerted effort by opponents to oust him.

A source close to the First Minister said Mr Yousaf was “absolutely not” considering his position following the chaotic events of Thursday.

His decision to end the Bute House Agreement with the Scottish Greens was branded an act of “political cowardice” by the smaller pro-independence party.

The Greens will back a no-confidence motion proposed by Scottish Conservative leader Douglas Ross, leaving Mr Yousaf facing a knife-edge vote at Holyrood next week.

Lorna Slater, co-leader of the Scottish Greens, told the PA news agency: “We no longer have confidence in a progressive government in Scotland doing the right thing for climate and nature.”

The Bute House Agreement gave the SNP-led government a majority at Holyrood but it came under strain in recent days after the Greens said they would put the future of the deal to a vote by their members.

Some in the Greens were unhappy at the Scottish Government’s recent dropping of 2030 climate targets and the decision to pause the prescription of new puberty blockers at Scotland’s only gender clinic.

With the Greens voting in favour of the no-confidence motion, there would be 64 out of 128 MSPs who do not back the First Minister.

The SNP have 63 MSPs at Holyrood while there is also Ash Regan of the Alba Party, who has not yet confirmed which way she will vote.

Alba leader and former first minister Alex Salmond said Ms Regan was now the “most powerful MSP in the Scottish Parliament” and told Times Radio she would write to Mr Yousaf setting out her demands on independence and women’s rights.

Presiding Officer Alison Johnstone can cast tie-breaking votes but would be expected to vote in favour of the status quo.

Any vote is likely to take place next week, with timings to be confirmed by parliamentary authorities.

The decision to end the Bute House Agreement means Scottish Green co-leaders Ms Slater and Patrick Harvie lost their ministerial roles.

Their MSP group met on Thursday afternoon to discuss their approach to the confidence vote.

Ms Slater said: “Today, the First Minister decided to tear up that agreement, to end the Bute House Agreement.

“And so we no longer have confidence in a progressive government in Scotland doing the right thing for climate and nature.

“So the Scottish Green MSPs will not be supporting Humza Yousaf in a vote of no confidence.”

She confirmed that rather than abstaining “we will vote in favour of a vote of no confidence” and claimed the First Minister had “caved in to the conservative, right-wing branch” of the SNP.

A spokesman for Mr Yousaf refused to say if he would quit if he lost the confidence vote, describing the question as “hypothetical”.

The SNP leader accused the Tories of game playing, insisting the powersharing deal with the Greens had “served its purpose” and lasted 19 times longer than Liz Truss’s premiership.