We still don't know the answer to this question, because Speaker John Bercow blocked a vote on the UK Prime Minister's Brexit deal today.
But we will get a sense of the level of support for the deal in Parliament tomorrow, when the first vote is held on the detailed legislation that turns it into law.
That vote will be on what is confusingly known as the bill's second reading. So which way will it go? CNN has attempted to estimate the level of support for Johnson's deal, based on information on how lawmakers voted on Saturday, their public statements, and other reports in other credible media sources.
For the deal: Johnson can count on the support of the 287 voting Conservative lawmakers, including 28 hardline Brexiteers who never voted for his predecessor's deal. He also has the support of 20 independent Conservatives, at least nine Labour MPs, and at least four independents -- including one, John Woodcock, who appears to have changed his mind. That takes him to 320 -- but in any vote, two MPs from this bloc would be nominated as tellers (counters of the votes), so that means he has 318 actual votes behind him.
Against the deal: Opposing Johnson are 231 Labour MPs, 35 members of the Scottish National Party, 19 Liberal Democrats, 10 Democratic Unionist Party MPs, five members of The Independent Group, 4 Welsh nationalists, three independent Conservatives and one Green MP. Another seven independent MPs would be likely to vote against the deal. That's a total of 315. Remove two tellers and you get a final tally of 313.
Three Labour MPs and one independent Northern Ireland unionist remain uncommitted, but are leaning towards supporting the deal.
Based on these calculations it seems that the second reading should pass tomorrow. It may even pass by a bigger margin than these numbers suggest. Some opponents of the bill may wish to ensure it gets to its next parliamentary stage simply in order to try and amend it -- perhaps by adding a provision for a second referendum, or keeping the UK in a customs union with the EU.