Cabinet ministers have wargamed how to respond if the Supreme Court rules against the Rwanda asylum policy that Rishi Sunak sees as “crucial” to his pledge to “stop the boats”.

New Home Secretary James Cleverly outlined the possible outcomes of Wednesday morning’s hearing during the first meeting of the Prime Minister’s new-look top team after a dramatic reshuffle.

Contingency measures have been drawn up behind closed doors in case the top justices side with the Court of Appeal ruling that removing asylum seekers to Kigali is unlawful.

Ministers are understood to have prepared for straightforward yes or no verdicts in the UK’s highest court, as well as the possibility the ruling is more complex.

Any outcome could end up with further appeals to the European Court of Human Rights in Strasbourg.

Downing Street said Mr Cleverly briefed the Cabinet on Tuesday of “some of the possible scenarios” as he took over from Suella Braverman after her sacking.

Leaving the European Convention on Human Rights was not discussed at the meeting, the Prime Minister’s official spokesman said.

But No 10 will be wary of Mrs Braverman launching an intervention with a call to leave the convention after she warned she has “more to say in due course” after being fired.

Contingency plans have been “discussed among Cabinet ministers”, the spokesman said, and “options for possible scenarios” have been prepared.

He made clear that the policy to remove asylum seekers who arrive in the UK by unauthorised means forcibly to Rwanda is a “crucial part” of the plans to halt Channel crossings.

Last month, the Home Office challenged a Court of Appeal ruling from June that overturned the High Court’s finding that Rwanda could be considered a “safe third country” for migrants.

Lawyers representing people facing deportation to the east African nation argue Rwanda is an “authoritarian, one-party state” with a “woefully deficient” asylum system.

But the Home Office has said the policy to remove asylum seekers to a “country less attractive” than the UK, “but nevertheless safe”, is lawful.

Five justices at the Supreme Court will give their verdict on Wednesday morning, before Mr Sunak faces Prime Minister’s Questions.

The Illegal Migration Act brought into law the Government’s policy of sending some asylum seekers to Rwanda.

However, the plans announced in April 2022 have been held up in the courts, with no deportation flights having taken place despite £140 million already being handed to Kigali.

Whereas Mrs Braverman repeatedly signalled she wanted out of the “politicised court”, Mr Cleverly said while foreign secretary in April he was “not convinced” the move is necessary.

He said that the European countries that are not signatories – Russia and Belarus – are a “small club”, adding: “I am not convinced it is a club we want to be part of.”

Mr Sunak has set stopping small boats of asylum seekers from arriving in Britain as one of his five pledges to the electorate.

But more than 27,300 migrants have been detected making unauthorised crossings of the English Channel so far this year, according to official figures.

The Supreme Court ruling by Lords Reed, Hodge, Lloyd-Jones, Briggs and Sales will be handed down on Wednesday after 10am.