JOHN McDonnell has been snubbed over the choice of a Holyrood candidate after trying to rewrite Scottish Labour policy on a second independence referendum.

The Shadow Chancellor lobbied to have Unison trade union organiser Simon Macfarlane chosen to fight SNP-held Maryhill and Springburn in 2021.

He recorded a video endorsing the fellow left-winger, urging local members to “make sure that you support Simon in this next election”.

He said: “I’ve known Simon Macfarlane for many years. He’s devoted his life to our local community and we hope that you will support him in Maryhill and Springburn to become a strong voice for you in the Scottish Parliament.”

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The Campaign for Socialism, the Scottish sister organisation to Momentum, promoted the clip on social media, calling it a “BIG ENDORSEMENT”.

However at the selection meeting on Friday, party members rejected Mr Macfarlane, and by 36 votes to 27 backed the more moderate Keiran O’Neill instead.

The rejection of Mr McDonnell’s pick came days after he caused turmoil in Scottish Labour by announcing a UK Labour government would not block Indyref2, contradicting Scottish leader Richard Leonard.

It caused Mr Leonard’s greatest crisis as Scottish leader, as he lost briefly control of his MSP group, and coincided with Scottish Labour general secretary Brian Roy quitting his job.

Mr McDonnell was then backed up by UK leader Jeremy Corbyn last Thursday, the day before the Maryhill selection, who said it was not up to Westminster to block a new vote.

A Scottish Labour source said of Mr Macfarlane’s failure: “This is a snub to John McDonnell after his attempt to ride roughshod over Scottish labour policy. After the way he humiliated Richard Leonard, members are furious with him and his hard-left supporters.”

Mr O’Neill, a GMB activist and secretary of LGBT+ Labour Scotland, voted for independence in 2014, but now supports a federal UK.

He said of his Yes vote in a Facebook video: “I now know that I have never been more wrong about anything in my life.”

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Scottish Labour said it was “ready to take the fight to the SNP and the Tories at the 2021 Holyrood elections” with members selecting “candidates across the country who will be champions for their communities, both inside and outside Parliament.”

The Maryhill seat was held by Labour’s Patricia Ferguson from 1999 until 2016, when she lost to the SNP’s Bob Doris, who flipped a Labour majority of 5,241 into an SNP one of 5,602.

After the seletion decision, Mr Macfarlane tweeted: “Thanks to everyone who backed me to be our candidate in Maryhill and Springburn. Sorry I didn’t do it but we have an excellent candidate in Keiran O’Neill. Onwards to a Labour victory.”

In a message to Mr Macfarlane on Twitter, Mr O’Neill said: “Thank you Simon for running a comradely campaign based on respect and socialism and for representing the absolute best of our movement. Looking forward to working with you and Unison to turn M&S red again.”