UK parliament's feuding factions

Here are the main camps in the Brexit battle among members of the 650-seat lower House of Commons:

FOR PM's Deal

The government: Everyone on the government payroll must back government policy -- or resign. Gareth Johnson quit his junior government post on Monday but there was no last-minute flood of resignations. Heavyweight cabinet Brexiteers like Michael Gove and Liam Fox are backing the deal for now. Conservatives have 317 seats in the House.

May loyalists: Backbench Conservative MPs who are firmly behind the government and are happy with the deal. Alarmingly few in number. With decision time approaching, a handful of Tories have changed their minds in recent days in favour of the deal.

Get it done: Conservative MPs who have reservations but just want to get a deal done and feel it is the least bad option. May's Downing Street office hopes to swell their ranks in the final hours.

AGAINST PM's Deal

Conservative Brexiteers: Led by Jacob Rees-Mogg, this faction also includes former foreign secretary Boris Johnson and former Brexit secretaries David Davis and Dominic Raab, who believe the deal delivers vassalage rather than independence.

Labour Party: Most of Labour's 256 lawmakers are pro-EU and will follow the party line. Leader Jeremy Corbyn wants to defeat the deal, then launch a vote of no confidence in the prime minister and trigger a general election, in which he would campaign to go ahead with Brexit, but renegotiate the deal. If this plan fails, the party is open to backing a second Brexit referendum.

Other opposition parties: The 35 Scottish Nationalists, 11 pro-EU Liberal Democrats, plus four Welsh nationalists and the sole Green MP are pro-EU and anti-Conservative.

DUP: May relies on the 10 Democratic Unionist Party MPs for a majority in parliament but they remain firmly against the deal, despite attempts to reassure them over the Irish border.

Conservative Remainers: A chunk of pro-EU Conservative backbenchers who also support the People's Vote campaign. They are led by former attorney general Dominic Grieve.

WAVERERS

Labour MPs in Leave-voting seats: May's best chance of victory could lie in persuading them to back the deal. She met with some Labour pragmatists last week and there are signs that they could be persuaded.

No-deal dilemma: Conservative and Labour MPs who have problems with the proposed deal but are also scared by the prospect of no-deal as the alternative. Will they blink first?