John McDonnell tells Jeremy Corbyn Labour Brexit policy a 'car crash'

Jeremy Corbyn has been rounded on by his closest ally John McDonnell who has branded the party's Brexit policy a "car crash".

A meeting of the shadow cabinet on Tuesday morning was widely expected to deliver a change in policy, towards explicitly backing a second referendum and campaigning to Remain.

Instead the Labour leader is said to have told colleagues the trade unions were not ready for the shift, resulting in "fiery exchanges" - sources told Sky News.

Mr McDonnell is understood to have said Labour's Brexit policy, hammered out last year, had fallen apart in a "slow motion car crash" which had seen votes leeching to the Liberal Democrats and Greens.

Labour's shadow chancellor previously told a climate change event on Monday it was the "right time to go back to the people" - and confirmed he would campaign for Remain in another referendum.

Mr Corbyn has been under pressure from several members of his top team, who feel that Labour's attempt to placate Leave and Remain voters led to humiliation at the European elections.

Mr McDonnell's intervention is significant as he is a staunch ally of the Labour leader who is thought to be frustrated by the glacial progress towards a change in policy.

He told journalists earlier in the day that he expected some "white smoke".

Deputy leader Tom Watson has been publicly calling for Labour to support remaining in the EU, and others have been pushing for a change in policy behind the scenes.

Emily Thornberry, the shadow foreign secretary, told Mr Corbyn: "This is about leadership."

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One source said: "Everyone expected a position change, and it's been delayed again. There were some fiery exchanges."

Unite leader Len McCluskey, Mr Corbyn's leading union backer, is sceptical of a second referendum.

In an article he wrote a month ago he claimed it would "pump more poison" into British politics. But other major unions back a second referendum.

The Labour leader has told colleagues he wants to wait another two weeks in order to consult union bosses at a meeting of Labour's National Executive Committee.

He was backed by some of his top team including party chairman Ian Lavery, as well as Rebecca Long-Bailey, John Trickett and Angela Rayner.

The Labour leadership is braced for party members - the vast majority of whom want to remain in the EU - to force a change in policy at the party's autumn conference.

A member of the shadow cabinet told Sky News Mr Corbyn "will be forced into this, the members won't accept another fudge. He should get on the front foot and show leadership before we're staring down the barrel of no deal."

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Sources close to the Labour leader point to remarks he made on a visit to Dublin after the European elections, in which he said there should be a "public vote" on a Brexit deal, but that this was "some way off".