John Swinney quits as Scotland's Deputy First Minister in surprise announcement

In a letter confirming he was standing down, Swinney said it had been an “honour to serve Scotland" and that he has always sought “to transform the life chances of everyone".

Writing to Sturgeon, he added: “Thank-you for the opportunity you have given me to serve my country.

“I am indebted to you for your leadership, constancy, friendship and loyalty.”

He said he would vacate his role once a new SNP leader is elected later this month.

Replying in a letter of her own, Sturgeon said her close friend and colleague "leaves a legacy to be proud of".

She said she was deeply grateful for the support, counsel and friendship he has always given me", adding she "could not have wished for a better partner in government".

Swinney had served as Scottish Deputy First Minister since 2014, taking over from Sturgeon after she became First Minister.

He had also previously served as finance secretary and education secretary.

Recalling how he joined the SNP at the age of 15 in 1979 at a time when the party’s prospects of electoral success were “poor”, he said he could “scarcely have imagined that over so many years I would have the opportunity to serve Scotland in Government in the way I have”.

Some party members had called for him to run in the race to replace her as First Minister but said he wanted to “create the space” for “fresh perspective” within the SNP.

He told Sturgeon he would continue at Holyrood as the MSP for Perthshire North, and looked forward to sitting on the back benches with her “to continue our contribution to Scotland’s cause”.

More to follow...