How Rishi Sunak's final throw of the dice on the Rwanda scheme could work - as he unveils the toughest migration law ever seen in the UK in a last-ditch bid to get flights off ground before the next election

The Government's new Rwanda legislation has been billed as the toughest immigration law ever seen in Britain.

Rishi Sunak told his MPs to 'unite or die' yesterday as the Government put in place a last-ditch attempt to set up removals flights heading to the East African nation by the next general election. But, following the resignation of immigration minister Robert Jenrick, will his controversial plan work?

WHAT DOES THE PLAN AIM TO ACHIEVE?

The legislation attempts to set out once and for all that migrants who arrive in Britain illegally, such as by small boat across the Channel, can be safely sent to Rwanda to claim asylum there rather than here.

The draft measures – entitled the Safety of Rwanda (Asylum and Immigration) Bill – are comparatively short, running to about 2,400 words across just ten legal clauses.

But despite its relative brevity, the Bill is trying to accomplish something that no government has attempted before.

It sets out a fine balancing of constitutional issues – including whether ministers or judges should have the final say on immigration matters.

On top of all that it is being done against a ticking clock, with a general election looming.

HOW WILL IT WORK?

It sets out unambiguously that the courts and tribunals must treat Rwanda as a safe country.

This is crucial because last month the Supreme Court ruled there was a risk migrants deported there could be sent on to another country where they might come to harm.

The legislation says that if migrants are sent away from Rwanda at a later date they can only come back to Britain, thus undermining the Supreme Court's main objection.

At a constitutional level the Bill says unequivocally that Parliament has sovereignty – rather than the courts.

It says aspects of international law which could block the scheme, such as the Refugee Convention, shall have no effect.

It also disapplies parts of the Human Rights Act, introduced by Labour in 1998, limiting the opportunities for legal meddling.

Further, it says only ministers – and not unelected judges – should decide whether to comply with interim injunctions from the European Court of Human Rights. The UK courts should ignore any interventions from Strasbourg, it adds.

This is important because the Strasbourg court used this kind of injunction to block the first attempt at removing migrants to Rwanda in June last year.

WHY IS IT SO CONTENTIOUS?

The Bill has divided opinion in the Conservative Party itself.

Remarkably, it prompted the resignation last night of Mr Sunak's immigration minister Robert Jenrick, who had wanted to see tougher measures. Right-wing Tories, including former home secretary Suella Braverman, have warned that any attempt to introduce watered down legislation would simply not work.

Mrs Braverman's allies said the Bill was 'fatally flawed'.

In particular, they criticised a 'loophole' which will allow migrants selected for removal to Rwanda to continue bringing legal challenges in this country based on their 'particular individual circumstances'.

The legislation does not set out what these circumstances might be, but it could cover asylum- seekers who claim they would face prejudicial treatment in Rwanda because of their sexuality, race or faith.

On the other hand, liberal Tories were concerned that the legislation would go too far.

One Conservative MP, Matt Warman, said on Tuesday that any moves to override the European Convention on Human Rights would have been a 'red line'.

Mr Sunak appeared to have talked them round last night.

The moderate One Nation Conservative caucus welcomed the draft Bill and indicated that they believed it stayed on the right side of international law – but said they would seek legal advice on the details.

Beyond the Tory Party the Bill will be even more divisive.

Home Secretary James Cleverly had to acknowledge yesterday that he could not say whether or not the new Bill was compatible with the European Convention on Human Rights. Legal experts said that the legislation is likely to face challenges in the courts.

COULD RISHI SUNAK HAVE GONE FURTHER?

Perhaps. But this was always going to be a difficult balancing act for the Prime Minister.

A statement from Rwanda's foreign affairs minister Dr Vincent Biruta, issued yesterday appeared to put that issue to bed, however. He seemed to indicate that his country would have pulled out of the deal if the new legislation had been more radical.

He also emphasised the importance of observing the 'highest standards of international law'. This will have been key in allowing Mr Sunak to urge his party to 'unite or die' behind the Bill.

WHAT HAPPENS NOW?

The Government has said it will fast-track the Bill through Parliament.

It is likely to face opposition in the House of Lords which could slow it down – but cannot block it completely.

Once it is on the statute book, the PM will have to decide whether to push ahead with the first Rwanda removals flights amid what is likely to be an avalanche of legal action.

It is likely to be his toughest test yet.