ONE of Jeremy Corbyn’s most prominent critics within the Labour party has backed Anas Sarwar in the Scottish leadership contest.

Former Chancellor Alistair Darling, who has vowed to “fight within” Labour against the UK leader, said Mr Sarwar was the best candidate to return the party to power at Holyrood.

Lord Darling famously wrote off Mr Corbyn’s chances in the June General Election as the campaign was just starting, saying the best he could hope for was a “sizeable opposition”.

The former Better Together chair also said Mr Corbyn was “the leader right up to the general election”, but added: “You know, leaders come and go."

After the election, Lord Darling suggested centrists in the party could wrest control back from Mr Corbyn and his left-wing allies.

Dismissing the idea of a breakaway party, he said: "I would rather fight within it to get the changes I would like".

Mr Sarwar last year signed an open letter for Mr Corbyn to resign, although he now says he wants him to be Prime Minister.

His opponent for the Scottish leadership, left-winger Richard Leonard, has repeatedly criticised those who turned against Mr Corbyn, accusing them of sowing disunity.

Lord Darling, who also backed Jim Murphy as Scottish leader in 2014, said Mr Sarwar’s support for the EU single market showed he was best placed to take on the Tories on Brexit.

He said the party needed a leader who was “unequivocally for staying in the UK and unequivocally pro-European”.

Mr Sarwar said at the weekend that he would protect Scotland’s place in the Union, and the offer of radical change through “socialism, not separation”.

Lord Darling said: “Labour is now in a three-way fight for the future of Scotland.

“Our next leader needs to be able to take on both the Tories and the SNP, both of whom will be fighting to be the biggest party in the Scottish Parliament.

“To beat them we need a leader who is unequivocally for staying in the UK and unequivocally pro-European. There is no doubt where Anas stands on both these crucial issues.

“Anas led the Labour campaign for a No vote in 2014. The fight against nationalism was tough. Not everyone would have shown the leadership Anas did, but he stepped up to lead an energetic campaign, visiting ever part of Scotland.

“Anas showed he can take on the SNP and win. Anas has the confidence and experience to lead. That’s why I’m supporting him, not just as next leader, but as the next Labour First Minister of Scotland.”

So far 28 Labour branches have endorsed Mr Leonard and 11 have backed Mr Sarwar.

The result will be declared on November 18.