How will the parties vote on Boris Johnson's Brexit deal in Westminster?

However, all of the parties which take seats in the House of Commons have already declared their voting intention.

Here’s how they will all vote:

SNP

Ian Blackford said all the evidence shows the UK will be poorer with the proposed Brexit deal

The SNP have said they will vote against Boris Johnson’s Brexit deal. Writing for The National yesterday, Europe Minister Jenny Gilruth said key Scots industries had been “betrayed by Tory ministers who have promised lots and delivered little”.

“We will not be complicit in voting for a deal which harms our fishermen, farmers and the educational prospects of the next generation,” she added.

The party’s position has been attacked by Unionists as “voting for a No-Deal Brexit”. Columnist Paul Kavanagh quipped that this was akin to “a mugger threatening to stab you if you don't hand over your wallet, then saying that you've freely chosen to be stabbed when you tell him to p*ss off”.

READ MORE: Jenny Gilruth: SNP cannot be complicit and vote for Boris Johnson's Brexit deal

Ian Blackford, who leads the SNP Westminster group which will vote in the Commons tomorrow, said: “All the economic evidence, including from the UK Government, is that we are all going to be poorer with this deal.”

Joanna Cherry MP added: “Scotland’s Government and representatives were cut out of the negotiations that led to [this deal]. Our country’s interests are not served by it. We won’t own it.”

Labour

Keir Starmer said the deal is 'not the deal the government promised - far from it', but still intends to vote for it

Keir Starmer will issue a three-line whip to instruct his party’s MPs to vote for the Tories’ Brexit deal.

Cherry labelled the move “foolish in the extreme but unsurprising” in an exchange with Scotland’s only Labour MP, Ian Murray.

Murray said: “My constituents and I are overwhelmingly against, and would be harmed by, a No-Deal Brexit - so I will NOT vote for no deal.”

Starmer is expected to face a significant rebellion among the Labour ranks as a result of his decision to vote for the deal. Prominent MPs including John McDonnell and Clive Lewis accused the party leader of “falling into the trap of rallying around this rotten deal”.

Starmer announced intent to vote for the deal without the legislation even being published. He has since called the deal a "thin agreement" and "not the deal the government promised - far from it", but still intends to vote it through parliament.

The move has been read as an attempt to play to Labour’s lost “Red Wall” seats, which were taken by the Tories over the issue of Brexit.

However, Scottish Labour will ignore Starmer and vote against the Brexit deal in Holyrood, according to the BBC's Philip Sim.

Northern Ireland’s parties

Sammy Wilson said the deal didn't address many issues that are damaging to Northern Ireland

All three of the Northern Irish political parties which take their seats in the Commons will vote down Boris Johnson’s Brexit deal.

The Alliance Party, the DUP, and the SDLP have indicated that they will not support the plan.

The DUP's Brexit spokesperson Sammy Wilson said the agreement did not address "many issues that are damaging to Northern Ireland" and so his party's eight MPs would vote against it.

Wilson said “many things have been left unaddressed and kicked down the road,” adding: "We expect [the government] to fulfil promises [it has] made to the people of Northern Ireland but [it hasn’t] done it to date, so don't expect our support."

SDLP MLA Matthew O'Toole said his party would not endorse the deal as it was “the biggest creation of trade barriers in modern history”.

Sinn Féin, the SDLP, the Alliance Party and the NI Greens oppose Brexit, while the DUP and TUV supported it. Unionist parties argue that Johnson’s deal will threaten the Union, given the border it creates down the Irish sea.

LibDems

Ed Davey's 11 LibDems will oppose the deal

Ed Davey’s 11 MPs will oppose the deal which their leader has called "last minute and threadbare".

Davey said it "puts up barriers to trade, barriers to business, making it harder and more expensive for British firms to export".

The party has changed position from being completely anti-Brexit, to saying that rejoining the bloc is “for the birds”.

Greens

Caroline Lucas said she could not be complicit in voting for the deal

The Greens only have one MP, Caroline Lucas. The representative for Brighton Pavilion said she would not be complicit in the creation of a “poorer, smaller UK with diminished global influence”, adding that “we have given up a three-course meal and what we’ve got in exchange is a packet of crisps”.

Plaid Cymru

Adam Price said no party that claims to stand up for working people would vote for the deal

The pro-independence Welsh party Plaid Cymru will be voting against Boris Johnson’s Brexit deal.

Party leader Adam Price criticised the “entirely false choice” between No Deal and the deal which has been struck. He also took aim at Labour for “swallowing the Tory lie” and backing Johnson's deal.

“No party that claims to stand up for Wales, or for working people, can do anything other than oppose this deal and the future it represents,” he said.

The Conservatives

Boris Johnson's party has a commanding majority in the Commons

Unsurprisingly, the party with a huge majority at Westminster will be voting to support the deal put forward by their leader.

In fact, with 78 more MPs than all the other parties combined, the Tories’ vote means the others are largely irrelevant.

Johnson’s biggest concern, in terms of winning the backing of his own party, was getting the approval of the influential European Research Group (ERG).

The ERG, a group of Conservative Brexiteers with no official government role but huge influence over policy, has declared its support for the EU trade deal.

READ MORE: Brexit trade deal means 'fall in quantity of fish' Scotland’s skippers can catch

After having lawyers read the 1246-page document in full, the group said the agreement, struck with Brussels on Christmas Eve, "preserves the UK's sovereignty as a matter of law".

The ERG's backing marks a significant boost for Johnson, after a number of its members withheld support for Theresa May's Brexit deal last year.

Johnson's deal will also be supported by Scottish Tories such as David Mundell, despite his previous threats to resign if the deal introduced different arrangements for Northern Ireland to the rest of the UK, as this one does.

Johnson shouldn’t struggle to extract a majority in the Commons from his party alone. With Labour’s backing, his Brexit deal is almost guaranteed to pass.