The quagmire that is Brexit took another dramatic turn as Britain’s Supreme Court ruled that Prime Minister Boris Johnson had acted unlawfully when he suspended parliament in a process known as proroguing.

Johnson had seemingly hoped to give as little time as possible to opposition MPs looking to force him to request an extension to Article 50 if he could not secure a deal to leave the EU.

MPs managed to force the legislation through anyway, helped by significant defections from the ruling Conservative party. 

Backed by Brexit die hards, the Conservative leader, has made clear that a no deal Brexit is a price worth paying to leave the EU.

If that sort of Brexit does materialise, the UK would cease to benefit from access to the bloc’s single market and customs union and would revert to trading with Europe and the rest of the world on World Trade Organisation rules.

This scenario is universally expected by analysts, including the government’s own to cause short term economic disruption and possible shortages of essential goods and medicines.

The prime minister now presides over a minority government, which lacks the votes needed to pass any legislation without opposition help. 

Here we consider a few possible outcomes:

Johnson secures a deal

EU leaders have so far refused to renegotiate a deal, which was offered to former Prime Minister Theresa May and flatly refused by parliamentarians, ultimately leading to her downfall.

The key sticking point for most MPs was the Northern Ireland ‘backstop’, which would have applied special rules to Northern Ireland should the UK fail to come up with a trade agreement with the EU during the transition period.

That backstop would have ensured that no hard border would be erected between Northern Ireland and the Republic of Ireland.

Any deal Johnson wants to reach would have to address this issue to secure backing from so-called hard Brexiteers but would do little to win support from the Conservatives and the opposition Labour Party.

The prime minister would have to put such a deal to parliament and win the resulting vote to ensure Brexit by October 31.

Johnson forces the UK out of the EU 

The British prime minister has repeatedly pledged to ensure the UK leaves the EU on October 31 and much of his popularity among Brexiteers is predicated on that promise.

Opinion polls show support for Johnson’s Conservatives crashing if the UK extends the date of Brexit beyond October 31.

However, unilaterally taking the UK out of the EU without a deal is near impossible without sparking the most severe constitutional crisis in the country’s recent history.

Parliamentarians have passed legislation forcing Johnson to attain a deal or otherwise request an extension when he meets EU leaders on October 17. No deal Brexit would then only be allowed to happen with the support of a majority in parliament.

One way around this roadblock for Johnson would be to win a General Election and revoke the measure but calling for a new vote requires an act of parliament itself, which he does not have anywhere near the two-thirds majority for.

Opposition leader Jeremy Corbyn is not willing to back an election until no-deal Brexit is taken off the table, putting Johnson into a Catch 22 situation.

Johnson could find a technicality to avoid an extension, but where it will come from remains to be seen.

Opposition forces a no-confidence vote

Labour have ruled out an immediate vote of no-confidence in Johnson’s government but if they did proceed with the option, the opposition would have 14 days to form a new government.

The government, which could take the form of a caretaker or unity government, would call for an extension to Article 50 before either renegotiating a deal with the EU or calling for an election.

Besides removing Johnson from power, at least temporarily, this would have little benefit for those opposed to no deal Brexit beyond a temporary delay unless a new deal with majority support is agreed upon by MPs.