It is difficult to overestimate how crucial the next week in British politics will be, as Boris Johnson tries to secure a Brexit deal with the EU and then get it approved by MPs.

Very little detail is emerging from “the tunnel” of negotiations between the prime minister and the EU.

But with a crunch European Council summit looming on Thursday and Friday, to be followed by the first Saturday sitting of the Commons since the Falklands war, there was still plenty to discuss on the Sunday shows.

The debate touched on how opposition parties will deal with a potential fourth “meaningful vote” on a Brexit deal, with Labour splits on whether to back it on the condition of a second referendum laid bare.

Tory Leavers meanwhile wrestled with potential compromises being made by Johnson.

And there was even time to talk private schools and Scottish independence.

Corbyn under pressure 

Labour splits over when to back a second Brexit referendum were laid bare as Jeremy Corbyn insisted an election should come first, but Rebecca Long-Bailey said the party should be prepared to back a “confirmatory” vote on Johnson’s deal.

The Labour leader signalled he was unlikely to formally back any attempt on Saturday to back Johnson’s deal in return for it being put to the public in a referendum versus Remain.

It put him at odds with shadow Brexit secretary Sir Keir Starmer who said over the weekend that if the PM gets a deal “then we will insist that it is put back to the people in a confirmatory vote”.

Corbyn told Sky News’s Ridge on Sunday: “I think many in parliament, not necessarily Labour MPs, others, might be more inclined to support it (if there was a referendum) even if they don’t really agree with the deal. I would caution them on this,” he said.

The Labour leader instead insisted he should first get the chance to negotiate a new deal as prime minister which would then be put to the public in a referendum.

But Long-Bailey became the latest shadow cabinet minister to pile the pressure on Corbyn, insisting Labour may have to back a second referendum before an election if Johnson’s deal passes the Commons.

She told BBC One’s Andrew Marr Show: “It has to be put before the people, any final deal, and they have to make a decision as to whether they are happy with that deal or whether they want to remain in the European Union.

“Now that’s the case if we are in a general election and Labour renegotiates a deal.

“And equally I think it should be the position if we are faced with a deal that’s passed through the Commons by an unelected Tory prime minister that could potentially be damaging for our economy.

Brexit compromises

According to reports in Brussels, Johnson is seeking to revive a Brexit plan first put forward by Theresa May for a customs partnership with the EU.

The scheme, intended to avoid the need for customs controls on the island of Ireland, would see Northern Ireland remain politically in a customs union with the EU but it would be administered by the UK.

It has created awkward questions for cabinet Brexiteers such as Jacob Rees-Mogg, who admitted he may have to “eat his words” having previously described May’s plan as “completely cretinous”.

Insisting he “trusts” Johnson in negotiations, Rees-Mogg told Ridge: “We’ll have to find out in a day or two whether I’ll have to eat my words or not – time will tell.

“There’s a line from Churchill saying that he often had to eat his words and he found it to be a very nourishing diet – and that is something that happens in politics.”

Home Secretary Priti Patel meanwhile moved to reassure the DUP, after its Westminster leader Nigel Dodds over the weekend told the Italian La Repubblica newspaper that Northern Ireland “must stay in a full UK customs union, full stop”.

Patel told Marr: “The withdrawal agreement was rejected in parliament three times on the basis of the backstop and on the basis that Northern Ireland would be treated differently.

“That is a situation that is unacceptable and quite frankly we have to make progress with this negotiation over the coming week and be prepared for whatever outcome.

“Northern Ireland, we have to ensure, will leave the customs union along with the rest of the United Kingdom – and that is effectively the position that we have made clear, the prime minister has made clear, as has the whole of government.”

Scottish independence

Scottish First Minister Nicola Sturgeon gave Corbyn another headache by making it clear the SNP would not prop up a Labour minority government unless it allowed a second independence referendum north of the border.

She told Marr: “I say this to Jeremy Corbyn or any Westminster leader who’s looking to the SNP for support, if you don’t accept Scotland’s right to choose our own future at a time of our own choosing, don’t even bother picking up the phone to me.”

Corbyn told Ridge a Scottish independence referendum was “not our priority”, adding: “We would certainly not countenance it in the early years of a Labour government.”

Private schools

Corbyn also appeared to row back on a Labour conference policy motion which said the party must scrap all private schools.

The Labour leader, who went to an independent prep school himself, described private schools as “elitist” but said: “Labour policy is to make sure private education is not a charity but pays tax just like anybody else and that the local education authority has far more influence over the way in which education operates.

“Obviously we’ll be deciding exactly what goes into the manifesto.”

Laughing out of the EU?

An odd moment on Marr, as the presenter upbraided Patel for “laughing” while he read out a list of industry groups worried about a hard Brexit.

Patel may have been smiling, but did not appear to be laughing.