The Westminster vote will be tight - with Boris needing about 320 votes in favour - bearing in mind the Speaker and Sinn Fein don't vote.
Presumably the 287 Tory MPs will back Boris!
He will hope some Labour defections will help - though these are unlikely. As are the 21 former Tory MPs to all support him; 6 to 8 are expected to vote against.
And the DUP have said they'll vote against; that's 10 votes.
Somehow the figures don't add up...