Edinburgh Alba MSP Ash Regan holds fate of First Minister Humza Yousaf in her hands

The future of First Minister Humza Yousaf and his government is hanging on the decision of Edinburgh Eastern MSP Ash Regan whether or not to back him in a confidence vote at Holyrood.

The tight arithmetic in the Scottish Parliament following the end of the SNP-Green power-sharing agreement means Ms Regan, who defected from the SNP to Alex Salmond's Alba party last year, has the crucial vote which could determine Mr Yousaf's fate.

Despite arguing repeatedly that the 2021 Bute House Agreement, which brought Greens into government for the first time, was "worth its weight in gold", Mr Yousaf called a special cabinet meeting on Thursday morning to end the deal. 

At First Minister's Questions a few hours later, Scottish Tory leader Douglas Ross announced he was tabling a motion of no confidence in Mr Yousaf.  And later Green co-leader Patrick Harvie said the Green MSPs would back the motion.

With 63 SNP MSPs and 65 opposition MSPs, the parliament is closely balanced. But if Ms Regan - the sole Alba MSP - decided to back Mr Yousaf, the numbers would be 64-64 and he would survive.

Alba leader Alex Salmond said Ms Regan would be writing to Mr Yousaf with a list of her priorities, including the need for progress on independence and guarantees about protection for women and girls.

He said: "She will set out her concerns and priorities in a letter and Humza's fate will depend on the reply to that letter."

Ms Regan, who has been Edinburgh Eastern MSP since 2016, stood against Mr Yousaf and former finance minister Kate Forbes in last year's divisive SNP leadership election following Nicola Sturgeon's resignation. 

If the vote of no confidence succeeds, Mr Yousaf would be expected to stand down and the parliament would have 28 days to choose another First Minister.

Mr Salmond said: "If Humza can't command a majority there should be somebody else who can. Maybe Kate Forbes could step forward into the breach."

The break-up of the SNP-Green partnership came just a week after the announcement that the Scottish Government was scrapping its target of a 75 per cent reduction in  emissions by 2030.  Green party members demanded a special meeting to vote on whether to leave government.

But amid ongoing discontent in SNP ranks over the deal, Mr Yousaf decided to move first and called Green ministers Patrick Harvie and Lorna Slater into Bute House on Thursday morning to tell them it was over.