WESTMINSTER should be recalled immediately if the UK Supreme Court this week rules against Boris Johnson, Jeremy Corbyn has insisted, as Labour prepares itself for a major Brexit showdown at conference.

And, as a new row broke out over procedure at the party conference in Brighton, the Labour leader risked infuriating a large swathe of Labour’s pro-Remain membership by suggesting a Brexit deal could be the best outcome, noting: “It depends on the agreement you have with the European Union outside.”

The 11 justices could make public their ruling as early as Monday. If they find the decision taken by the Prime Minister to suspend the UK Parliament for five weeks was unlawful, then there will be calls for Mr Johnson to resign.

Any such decision would disrupt not only this week’s Labour conference but also next week’s Conservative one as MPs travel back to the House of Commons.

The Labour leader told the BBC’s Andrew Marr Show: “If the Supreme Court, and it is an if…decide Parliament should be recalled - in other words, the advice he gave was wrong - then we would seek to take immediate action in Parliament to prevent him closing down Parliament all the way through to October 31. So, I would work with the other opposition parties as we have up to now.”

He added: “The Commons should be recalled if that is what the Supreme Court decides and I hope we’re in that position because I want…our Parliament to be able to question the Government. This is pretty strange behaviour when you’ve got major decisions coming up,[that] the Government, the Prime Minister closes down Parliament to prevent any scrutiny or debate.”

Dominic Raab refused to be drawn on whether the UK Government would seek to resuspend Parliament if it lost the court case.

The Foreign Secretary said: “I’m very keen not to get ahead of ourselves on this. And I’m also keen not to take levers off the table, that weaken the position of the UK in Brussels.

“But can I also say in relation to the Supreme Court, one of the reasons I campaigned to leave the EU is because I want our judges to have the last word on the law of the land and not for that to be decided by European judges in Luxembourg. So, it is absolutely vital that we respect the role of the Supreme Court in our justice system but also in our democracy,” he added.

This lunchtime it emerged that Labour’s ruling National Executive Committee was set, via email responses, to back Mr Corbyn’s proposal that party policy at the forthcoming General Election should be to support a referendum setting out a choice to the public between a credible Leave option - ie a Labour government’s deal with the EU - and a Remain option and, following the election of a Labour government, for the party to agree its final approach to the Brexit issue at a special conference.

However, the conference debate is also set to include calls from senior figures and local parties for Labour to formally swing fully behind Remain now.

This sets the stage for a passionate debate within the next 48 hours but it is thought the main trade unions are supportive of Mr Corbyn’s approach, and will vote for it; given the unions have 50 per cent of the conference votes, then the leader is likely to win the day.

One disgruntled pro-Remain Shadow Cabinet source branded the process a “total stitch-up”.

But asked, if conference voted for Labour to be unequivocally a Remain party, would he abide by the vote, Mr Corbyn told the Marr programme: “Listen. I’m leading the party, I’m proud to lead the party, I’m proud of the democracy of our party and, of course, I will go along with whatever decision the party comes to.

“But I just simply say, and I’ve said this to everybody, please remember why people voted Leave, why people voted Remain but also remember there is more that unites all of those people - over austerity, over investment, over education, over housing, over health, over a green industrial revolution - than there is that divides.”

James Cleverly, the Tory Chairman, said: “Jeremy Corbyn this morning refused nine times to say if Labour would support Brexit even if they negotiated a deal with the EU themselves, showing Labour offer nothing but dither and pointless delay.

“Jeremy Corbyn can’t lead his own party, let alone the country; he can’t even make up his mind on the most important issue facing the country. He would delay Brexit until at least 2020 and even longer if the EU demand it; Brussels would be in the driving seat and Corbyn would accept anything from them.”

He added: “Only Boris Johnson and the Conservatives will get Brexit done by October 31, whatever the circumstances, and get on with delivering the change that people voted for.”

Tom Brake for the Liberal Democrats said: “Jeremy Corbyn has once again refused to deny that if he becomes Prime Minister his government will be a Brexit government.

"This will be deeply concerning to millions of Labour supporters who want to campaign to stop Brexit and cannot get any clarity from Labour.”

He added: "People who want to stop Brexit must support the Liberal Democrats, the strongest Remain party. In a general election, every vote for the Liberal Democrats will be a vote to stop Brexit."