Could Boris Johnson's Brexit deal pass through parliament?

The prime minister needs 320 MPs to get his deal over the line but political parties and powerful factions in Westminster have their own red lines when it comes to supporting him. Some will never support him at all and others might back a deal if it had a confirmatory referendum attached or extra reassurances on workers’ rights and environmental protections. These are the demands of all the key groups.

Conservatives

The vast bulk of the Conservative party voted for Theresa May’s deal and will vote for Johnson’s deal, whatever he comes back with. Most of the party just want to get Brexit through, making up 260 MPs.

Tory ‘spartans’

This group of 28 hardline Brexiters hated May’s deal because of the proposed Northern Irish backstop, which contributed to it failing in the Commons three times. They may be satisfied with Johnson’s compromise, which involves a form of Northern Ireland-only backstop, and promises of an independent trade policy. However, some still have concerns about Northern Ireland remaining aligned with the EU on customs and it is not clear if all of them could still support a deal if the DUP is not on board. Steve Baker, the chair of the European Research Group, said he was optimistic about supporting a “tolerable” deal but the group as a whole would reserve judgment until it had seen the legal text.

The Tory anti-no deal rebels

This group of expelled Tories – kicked out for trying to block a no-deal Brexit – numbered 21. Sam Gyimah has since joined the Liberal Democrats, but these ex-Conservatives are mixed on whether they would now back a deal. Most of them will probably support Johnson because it removes the scenario of crashing out of the EU. The former chancellor Philip Hammond wants a far closer economic relationship than what is being proposed, and the backbencher Antoinette Sandbach would like a second referendum. Another of those expelled, Margot James, told the BBC she was likely to give a Johnson deal the “benefit of the doubt”, but she felt his current proposal was worse than May’s.

Democratic Unionist party

The Democratic Unionist Party (DUP) is a Northern Ireland unionist political party, founded by Ian Paisley in 1971. The party is currently led by Arlene Foster.

The DUP achieved their best ever general election performance in 2017, and have 10 of Northern Ireland’s 18 constituency MPs at Westminster, where they are led by Nigel Dodds. Since the election they have been supporting Theresa May’s Conservative government in a confidence-and-supply agreement.

The DUP supported leave in the EU referendum, and have repeatedly expressed their concerns over the provisions for an Irish border backstop. This led to them voting against Theresa May’s Withdrawal Agreement with the EU in parliament’s three ‘meaningful votes’. Getting them to back any new Boris Johnson Brexit plan for the island of Ireland is seen as key to him getting parliamentary backing for a deal.

Northern Ireland voted to remain in the EU.

Devolution and power-sharing in Northern Ireland, where the DUP had held the position of First Minister since 2007, collapsed in January 2017, and has not been restored despite several attempts, most recently in the wake of the murder of journalist Lyra McKee.

Martin Belam

The Northern Irish party is the most important piece of the jigsaw, and the assumption is that if its 10 MPs agree to Johnson’s deal, then Eurosceptics will fall in behind them. Ultimately the DUP wants to be able to tell voters in Northern Ireland that it remains part of the UK and will not be cut adrift by Westminster. The significant sticking point is over how in future the party might give its “consent” to the deal and future alignment with EU regulation. The DUP wants certainty that it would be able to block continued proximity to EU rules through the Northern Ireland assembly, once it is up and running again.

Labour

Labour will never vote for a hard Brexit deal proposed by Johnson, and ultimately Jeremy Corbyn wants to broker his own agreement with the EU should he become prime minister. This would have to involve stronger protections for workers’ rights, the environment, security for EU citizens and a customs union with the EU. However, there could be some pressure from the party’s pro-remain wing to allow a Johnson deal if the government agreed to tack on a confirmatory referendum to get it through.

Labour MPs for a deal

While the party leadership will not back a Johnson deal, it is a different story for some of the party’s backbenchers in leave-voting seats. About 19 Labour MPs are potentially up for voting for a deal – if there were stronger protections on workers’ rights, the environment and the future relationship. They might be minded to back a deal from Johnson as it removes the threat of no deal, presents an “orderly Brexit” and avoids a further delay.

Liberal Democrats

A second referendum is official policy for the anti-Brexit party and its leader, Jo Swinson, has tabled a motion to get this decision back before MPs via an amendment to the Queen’s speech. She has been fairly receptive to suggestions that the party could back Johnson’s deal if it also offered a second vote.

The Scottish National party

The party also backs a people’s vote but even if this is offered as an option by the prime minister, the party will not back any kind of deal that takes Scotland out of the customs union and single market. Another Scottish independence referendum is the SNP’s main priority and since Johnson is almost certainly unlikely to accept that request, or incorporate it into his deal, it is hard to see how the party could ever back him. The SNP also urgently wants a general election and the most likely route to one is if the prime minister fails to get a deal through parliament.