Well, despite the Prime Minister's 'my timetable' or 'election' posturing, the truth is several options are on the table.
- 2/3 majority in favour or
- A short bill bypassing the 2/3 requirement - but needing to get through all parliamentary stages and risking amendments
But it's inevitable that how the EU reacts (or doesn't) to the vote tonight will influence how MPs and the Government respond next.