Labour’s divisions over Brexit have deepened as Jeremy Corbyn pushed for the party to delay a decision on whether to support staying in the European Union until after a general election.

A statement backed by Mr Corbyn setting out his position was emailed round the party’s National Executive Committee (NEC) and endorsed without a formal meeting, despite opposition from some members of the body.

Unite union boss Len McCluskey, a key ally of the Labour leader, called on the party’s senior figures to fall in behind the policy or “step aside”.

Labour’s plan would see a government led by Mr Corbyn negotiate a new deal with Brussels before calling a referendum.

Labour Party Conference
Shadow foreign secretary Emily Thornberry at the Anti-Brexit ‘Trust The People’ march and rally during the Labour Party Conference in Brighton (Gareth Fuller/PA)

The party would remain neutral about whether to back remain or the Labour-negotiated deal until a decision was taken at a special conference.

Mr McCluskey told Sky News’ Sophy Ridge on Sunday: “We must go in to an election united and when we have a policy on Brexit and Jeremy Corbyn makes it clear that that is the policy then that is what leading members of the shadow cabinet should argue for.

“If they find that they can’t argue for it because they feel strongly, well of course they have that right but they should step aside.”

On BBC’s Andrew Marr Show, Mr Corbyn suggested that it could be possible for the UK to be better off out of the EU.

It “depends on the agreement you have with the European Union outside”, he said.

“We would want to hold a consultation, a special conference of our party at the point that we have got this offer from the EU, we’ve got this as a remain – and hopefully reform – option.”

He added: “I will go along with whatever decision the party comes to.”

But shadow foreign secretary Emily Thornberry – whose actions were singled out by Mr McCluskey – deputy leader Tom Watson and London Mayor Sadiq Khan insisted the party must throw its weight behind the remain cause now rather than at a special conference after an election.

Activists are continuing to push for a vote at the party’s conference in Brighton to commit it to the remain cause.

Mr Khan said Labour MPs should be whipped to back the position, insisting the party could not remain neutral.

Labour has come to a vital crossroads. At conference this week, we have the opportunity to come together to define how…

Posted by Sadiq Khan on Sunday, September 22, 2019

Mr Watson, who survived a bid to oust him – in part over his views on Europe –  told a Labour conference fringe event in Brighton: “Apparently, the reason (Corbyn-supporting Momentum group chief) Jon Lansman tried to abolish me is because of my support for remain.

“Well I have got one message for Jon Lansman, I’m remaining. I might have lost a bit of weight – but I’m no push over.

“We are not going to have these silly factional shenanigans that have been undermining the unity of this conference, delaying us any more.”

He added: “We are a remain party. We are a European Party. We are an internationalist party.

“That is who we are. Not perfect, not pure. But overwhelmingly committed to Britain remaining in Europe.”

Ms Thornberry said Labour must lead the campaign to remain in the EU – even if it meant rejecting a deal they had negotiated with Brussels.

She insisted it was not disloyal to call for Labour to back remain, stressing it was the best way to win power.

“When people here today take a position that they want a second referendum and we want to remain, that doesn’t mean that we are not socialists or that we are disloyal to Jeremy Corbyn.

“It is entirely because of our commitment to socialism and our loyalty to Jeremy that we are out, today, demanding the outcome which will give us the best chance of putting Jeremy into No 10 and putting into practice the socialist policies that we set out in our 2017 manifesto.”

Mr Khan said:  “I’m making a direct appeal to delegates at Labour conference: do not accept any ‘compromise’ on Brexit, do not accept a fudge, do not delay us setting out what our stance would be in any future referendum.

“Labour is a remain party and we need to make this official by making it our policy to campaign to stay in the European Union under all circumstances – and to whip all our MPs to back that position.

”Staying neutral in the face of the biggest economic and social threat to our country for decades is simply not an option.”

In an open letter to Mr Corbyn – signed by shadow treasury minister Clive Lewis – the Another Europe Is Possible group said: “It would be a serious failure of political leadership by our party if we are unable to take a position on the most immediate political and economic question of the day.”

The added: “Leadership is not about standing back but stepping forward.”

A behind-closed-doors meeting to thrash out a Brexit policy motion will take place on Sunday night ahead of an expected conference vote on Monday.