Brexiety.
Labour are now in a position to play a blinding game. Labour MP's either abstain or vote for the Bill. Either way if their votes carry the Bill they will be seen to have saved the country from a No Deal Brexit, which everyone now knows ( surely???) will be a catastrophe. When the realisation dawns that it was Labour who saved the day, a General Election will be called and Labour will win. Tory voters will be so utterly disenchanted with their party, they will stay at home and drink tea. The Labour Party offer a 'People's Vote' as part of their manifesto and romp home. Brexit will be dead in the water, we will have a Labour government (which certainly wasn't the plan) and the Tory Party will be dust.