It is being reported that there will be a series of votes on the 12th, 13th and 14th of March:
The prime minister said she will put her withdrawal agreement - including any changes she has agreed with the EU - to a meaningful vote by 12 March.
If that fails, MPs will be offered two separate votes:
One, on the following day, on whether MPs support a no-deal Brexit - so the UK would "only leave without a deal on 29 March if there is explicit consent in the House for that outcome"
If that fails, then MPs will get a vote by 14 March on requesting an extension to the two-year Article 50 negotiation process to delay EU withdrawal beyond 29 March
But what happens if Parliament votes against each of these? That is, what happens if Parliament votes against Theresa May's deal on the 12th, votes that it does not support a No Deal Brexit on the 13th, and then votes against extending the date of departure on the 14th? Firstly, what is the "will of Parliament" deemed to be in this case, and secondly, what are the practical consequences? The default, of course, is that the UK leaves on the 29th of March without a deal; yet Parliament will have said (in its vote on the 13th) that it does not support this eventuality.