The timetable is extremely tight for a general election on either December 9 or December 12.
If polling day is December 12 – the Government’s preferred date – then dissolution of Parliament would need to take place at one minute past midnight on November 6.
MPs’ last day in the House of Commons would be November 5, the day after they are due to choose a new Speaker to succeed John Bercow.
Mr Bercow is standing down on October 31.
For a December 12 general election, the deadline for candidates to submit their nomination papers would be November 14, and the deadline to register to vote would be November 25.
The deadline to apply for a postal vote would be November 26.
Were polling day to be December 9, dissolution of Parliament would need to happen at one minute past midnight on November 1.
Any legislation needed for an election to take place on December 9 would therefore need to be rushed through Parliament by Thursday evening this week.
Under this scenario, the deadline for candidate nominations would be November 11, the deadline to register to vote would be November 20, and the deadline for postal votes would be November 21.
Both timetables would incorporate a bank holiday in Scotland on December 2, and a summit of Nato leaders in London – including US President Donald Trump – on December 4 and 5.
There is also time under both scenarios for MPs to return to the House of Commons before Christmas, albeit briefly, to resume parliamentary business.