Yahoo News Super Saturday: Why is Parliament sitting this weekend and when will the Brexit vote take place?
Parliament is sitting today in what could be one of the most important Commons’ sessions of the entire Brexit process. It will consider the Brexit deal that Boris Johnson has secured in Brussels.
Parliament has only sat on a Saturday on three occasions since the outbreak of the Second World War, and even before then it was a rare occurrence.
The last time the House of Commons convened on a Saturday was after Argentina invaded the Falklands in 1982.
Why will they sit?
On Thursday, Mr Johnson secured a series of changes to the Brexit Withdrawal Agreement and Political Declaration.
The changes to the former mean that the backstop is replaced by an effectively permanent protocol which applies to Northern Ireland only and leaves the whole of the UK to negotiate free trade deals around the world.
The changes to the latter loosen the provisions which would have stopped Britain from deregulating.
Parliament must now consider the deal and vote on whether to approve it.
With the DUP refusing to support the deal, the vote could be incredibly tight and will depend on whether Mr Johnson can retain the support of his own hardliners while also winning back former Tories and convincing two dozen or more Labour MPs to rebel against their leader.
What numbers are needed in Commons for deal to pass?
The Government needs at least 318 votes for a majority.
If every Conservative MP who is able to vote backs the deal, it gives the Government 285 votes.
Mr Johnson has refused to say whether he would restore the whip to the 21 Tories he exiled for previously voting against his will.
What happens if it's passed?
If MPs approve the deal on Saturday, the Government is expected to table the Withdrawal Agreement Bill on Monday. MPs could amend it to add a second referendum.
If it passes unchanged, the UK leaves the EU on October 31, as promised by Mr Johnson.
What happens it's rejected?
If Parliament rejects the deal then the so-called Benn Act requires the Prime Minister to request an extension to the Brexit process.
Jean-Claude Juncker has indicated the EU could reject that, and the UK would have to leave with no deal on Oct 31 or cancel Brexit.
What other options could MPs take?
The Letwin amendment
Sir Oliver’s Letwin amendment - if picked by John Bercow for MPs to consider - invites MPs to change the Government's motion to withhold support for the deal "unless and until" the legislation is passed that would give it legal effect - i.e. the Withdrawal Agreement Bill. By delaying approval, it would force Boris Johnson to seek an extension to Article 50, as required by the deadline set out under the Benn Act.
This move is driven by the fear that the Government could engineer a no-deal Brexit on October 31st by securing approval for its deal this Saturday, thereby exempting Boris Johnson from the legal obligation under the Benn Act to seek a delay to Brexit, only then to ensure the bill implementing the deal never makes it into law, leaving MPs with no time to push through any further legislation to avoid such an exit.
Bid for unity government
If MPs reject the deal outright and Mr Johnson tries to undermine the request of an extension from the EU, MPs could be forced into a vote of no confidence to remove the PM.
If they do that they would need to try and form a so-called unity government to secure an extension and perhaps legislate for a referendum. Eventually, there would need to be a general election.
Confirmatory referendum
Another option could be for MPs to attach a confirmatory referendum to the deal, so that the country would vote again. There have been reports that Jeremy Corbyn now supports such an approach.
If Mr Johnson pulls the Bill, the UK could head for no deal. Again, Europhiles could try to topple him and form an emergency government to have a public vote.
However, it's unlikely that a parliamentary majority for a referendum could survive the many, many votes to pass a referendum law.
MPs could also try and amend the deal in other ways, for example by forcing the Government to pursue a softer Brexit in the future relationship negotiations.
Three-month extension
If the EU grants an extension until Jan 31, it is not likely to be long enough for a new referendum, and unless fresh concessions are secured, the UK will be in the same boat on January 31.
