Here’s some of the possible scenarios that could follow Tuesday’s historic ruling:
Vote of no confidence
Labour could bring forward a vote of no confidence in the government to oust Boris Johnson and bring about a general election, potentially via a government of national unity.
Jeremy Corbyn is however ruling out this route because Labour doesn’t want a general election until the Brexit deadline of October 31st is extended.
He says he wants an election, but only when a no deal Brexit is off the table. Boris Johnson has however continually insisted he will not ask for an extension beyond Halloween.
Government proposes an election
Boris Johnson could bring forward another vote on a general election. He has already done this twice unsuccessfully, and for the reasons stated above, it would almost certainly fail again.
Labour also doesn’t trust that Boris Johnson will agree to hold an election and then change the date when Parliament is suspended, to allow him to push through no deal.
The reason for the government proposing it would be to hammer home the message to voters that Jeremy Corbyn is running scared, Parliament is denying the people a say and stopping the Prime Minister delivering the result of the referendum.
Vote on conference recess
The Conservative Party conference begins on Sunday and is due to finish next Wednesday. In normal times, MPs vote to put parliament in recess during conference season to allow them to go off and have their fun.
However, having denied Parliament that chance this year by suspending it, there is pretty much zero chance MPs will vote with the government to allow the Tories to treck up to Manchester for what would be a four-day election rally.
Instead, it’s likely ministers will have to go back and forth from Euston to Manchester Piccadilly to ensure they make their speeches to Tory members and also be in Parliament for any surprise votes that the opposition might spring on the government.
Boris Johnson has scheduled a Queen’s Speech for October 14th to set out, he says, his programme for government. Indeed, that’s why he said he had prorogued Parliament in the first place, an argument the Supreme Court rejected.
If he still wants to go ahead with the Queen’s Speech, the Prime Minister will have to prorogue Parliament at some point - that is the normal and proper procedure to allow both Houses to prepare for the arrival of the Queen (security, dress rehearsal etc).
Lady Hale declared in her ruling that “four to six days” would be normal before such an occasion, meaning Boris Johnson could lawfully suspend parliament on October 4th. That would only give MPs a few days to debate before again Parliament is shutdown.
A Brexit deal
The government is still in negotiations with the EU. Progress is, at best, moving at a snail’s pace.
Number 10 wants the backstop removed, but have yet to come up with an alternative that Brussels will accept. The words between the two sides have got warmer but the cold reality is a deal is looking unlikely before Halloween.
Bring back May's deal
One option being considered by some MPs, including former minister Rory Stewart, is to bring back Theresa May’s deal (the current Withdrawal Agreement). Despite being rejected three times by Parliament, there are a number of Labour MPs who’ve suggested they may now vote for it.
Other MPs may agree to vote for it if they can attach a second referendum to it.
It’s not exactly clear how they would bring the deal back, (possibly via something called Standing Order 24), or whether there’s a majority for it. Then there’s the question of whether a Boris Johnson government would go ahead and implement it if it did pass.
Those arguing against the government’s unlawful prorogation convinced the 11 Supreme Court judges that they were being denied time to debate Brexit at a crucial moment in the nation’s history. So how will they now use the time they’ve been given?
Wednesday is likely to see the Speaker grant MPs urgent questions, summoning government ministers and possibly to the Prime Minister to update the House on Brexit talks.
MPs could seek to get more detail on the advice the Attorney General gave the Prime minister ahead of prorogation. They could also prone more on the government’s latest preparedness for a no deal Brexit.
In truth there is an almost endless list of questions MPs can ask on this issue, but they have already passed the most crucial legislation they need to stop a no deal Brexit with a law that compels the Prime minister to go to Brussels and seek an extension to January 2020 if he fails to get a Brexit deal.
Boris Johnson though, as stated, says he will not do that, meaning we could soon end up back in the courts.
For now though, we are stuck in Brexit purgatory.
What we do know, is on Wednesday Leader of the Commons Jacob Rees-Mogg will set out government business when parliament re-opens.