Jeremy Corbyn will make his keynote speech to the Labour Party conference a day early after the Supreme Court declared the five-week prorogation of Parliament unlawful.

Speaker John Bercow said the Commons will resume on Wednesday morning in light of the judgment, and Labour sources said Mr Corbyn will instead take to the stage at 4pm on Tuesday afternoon.

The party’s deputy leader Tom Watson was due to make a keynote address at the Brighton gathering on Tuesday, but has cancelled his appearance after it was moved to Wednesday.

Mr Watson said: “This is a momentous day. It’s right that Jeremy closes the conference this afternoon.

“I’ll be in London tomorrow to hold our law-breaking Prime Minister to account. I’ll save the speech I was going to conference make until next year.”

It comes after a panel of 11 justices at the Supreme Court in London ruled unanimously that the Prime Minister’s advice to the Queen to suspend Parliament until October 14 was unlawful because it had the effect of frustrating Parliament.

The decision has led scores of conference attendees to dash back to Westminster – and the moving of Mr Corbyn’s speech will effectively curtail the conference.

PA understands Labour MPs have been told by party whips to return to the Commons for 11.30am on Wednesday.

However, Labour insisted that the conference would still go on.

A Labour spokeswoman refused to say if the party would table a confidence motion in the Government when the Commons resumes.

Mr Watson had been due to tell party members that Labour should stop infighting and instead focus on tackling the Tories.

Labour Party Conference
Labour’s deputy leader Tom Watson was due to make his keynote address on Tuesday (Victora Jones/PA)

He was expected to seek to draw a line under the “damaging, divisive and unnecessary” failed bid to oust him which cast a shadow over the start of the conference.

And the frontbencher had been due to provocatively claim Mr Johnson is placing the country in the greatest danger it has faced since being confronted by Hitler’s Nazis in 1940.

Mr Watson survived a call for his position to be abolished just hours before the party’s conference in Brighton began on Saturday.

He was expected to say: “I didn’t choose the row going into this vital week for our party and our country, I didn’t want it, I didn’t seek it and I regret it.

“It was damaging, divisive and unnecessary. Unfortunately we cannot pretend it didn’t happen. But let us now draw a line under it.”