Theresa May seems to have finally found a way to unite Remainers and Leavers – unfortunately for her it is in opposition to her Brexit deal.

Ahead of the crunch vote in the Commons, why do so many MPs loathe her deal?

– Brexiteers claim the deal risks leaving the UK a ‘vassal state’ bound by Brussels’ rules without any say over them

Their concerns mainly focus on the backstop measures aimed at preventing a hard border with Ireland, under which the UK would be in a “single customs territory” with the EU, while Northern Ireland would remain aligned with many Single Market rules.

Prominent Eurosceptic Jacob Rees-Mogg said “in some areas it will leave the United Kingdom with even less control than it currently has: the vassal state”.

Former foreign secretary Boris Johnson said the UK would be a “satellite state” of Brussels.

In his resignation letter, former Brexit secretary Dominic Raab said “no democratic nation has ever signed up to be bound by such an extensive regime, imposed externally without any democratic control over the laws to be applied, nor the ability to decide to exit the arrangement”.

There are also concerns about the extent to which the UK will seek to remain aligned with the EU under the terms of any deal aimed at avoiding the need for the backstop – many Brexiteers would prefer a looser, Canada-style free trade agreement.

– The DUP’s ‘blood red’ line on avoiding a border down the Irish Sea

The 10 DUP MPs prop up Mrs May’s administration in the Commons but that support appears to have collapsed over the Brexit deal.

They will not accept any measure which effectively creates a trade barrier down the Irish Sea between Great Britain and Northern Ireland – something they believe the backstop does.

DUP leader Arlene Foster told her party’s conference in November that “as things stand we would be sowing the seeds of inevitable economic divergence from our largest market” in the rest of the UK.

– Labour says the deal fails to meet its tests for a ‘jobs-first Brexit’

Jeremy Corbyn | Brexit Statement

Two years of botched negotiations in which Theresa May’s red lines have been torn up, Cabinet resignations have been racked up and Chequers has been chucked.

Posted by Jeremy Corbyn on Thursday, November 22, 2018

Jeremy Corbyn said any deal would have to include “a permanent customs union” with the UK having a say over future trade agreements, a “strong single market deal” and “guarantees on workers’ rights, consumer and environmental protections”.

– The Opposition also sees the vote as a way to oust Mrs May and install Mr Corbyn in Downing Street

Labour’s official policy is to call for a General Election if Mrs May fails to get her Brexit plan through Parliament.

It is “inevitable” the Opposition would move a motion of no confidence in Mrs May’s government if she loses the vote, shadow Brexit secretary Sir Keir Starmer has said.

– Pro-EU MPs hope for a second referendum

Some MPs hope by rejecting Mrs May’s deal, they can push for the final decision on Brexit being handed back to the public.

Former transport minister Jo Johnson quit the government in November as the finishing touches were being put to the deal and said the public should be asked to vote again in order to avoid the choice between “vassalage” of the deal and the “chaos” of a no-deal Brexit.