In fresh turmoil, the Rwandan government immediately responded to the move by warning that it could pull out of the deal if the UK fails to comply with international law.
Mr Sunak failed to head off a major rebellion by the right of the party after choosing not to opt out of the European Convention on Human Rights (ECHR).
Ms Braverman’s cabinet ally Robert Jenrick, the hardline immigration minister, was said to be on resignation watch over Mr Sunak’s choice not to bypass the ECHR.
In a fiery Commons speech, Ms Braverman said: “The Conservative party faces electoral oblivion in a matter of months if we introduce yet another bill that is destined to fail… Do we fight for sovereignty or do we let our party die?”
Mr Sunak now faces the near-impossible task of winning support from Tory right-wingers who wanted a “full fat” move on the ECHR, and centrists in the ‘One Nation’ group warning they cannot back legislation that flouts human rights law.
The bill includes explicit provisions to disapply relevant parts of the Human Rights Act so they cannot be factored into court decisions on deportation cases – but does not try to disapply the ECHR.
However, the legislation will ensure UK ministers “retain the decision on whether or not to comply” with interim orders from the European Court of Human Rights – the Strasbourg body that oversees the ECHR.
Mr Sunak defended his plans at a showdown meeting of the 1922 Committee of Tory backbenchers on Wednesday. A source close to Ms Braverman made clear that the bill doesn’t come close to meeting her tests. “It is fatally flawed,” the ally said. “It is a further betrayal of Tory voters.”
Angry at his failure to act on the ECHR, some Tory right-wingers submitted letters of no confidence in Mr Sunak on Wednesday, according to ITV presenter Robert Peston.
Hardliners on the right – including members of the New Conservatives, Commons Sense Group and European Research Group – met again on Wednesday evening. The rebels are convening a “star chamber” of legal experts to decide if the new bill is tough enough to support.
The Independent understands many are unhappy with the middle way option to disapply the Human Rights Act. One senior MP said there would be “no purpose” to the bill if it fails to get around all human rights legal challenges.
Senior Tory moderate Damian Green, chair of the One Nation group – which boasts support from around 100 MPs – has warned Mr Sunak that he “should think twice before overriding both the ECHR and HRA”.
As spokesman for the One Nation said it welcome the government’s decision to stick with “international commitments” – but is taking legal advice on whether it can now support the bill.
The front page of the legislation concedes that the government is unable to say whether the bill is compatible with the ECHR – an admission that may make moderates uneasy about voting for it in parliament in the days ahead.
Responding to the bill, Rwanda’s foreign affairs minister Vincent Biruta warned the Sunak government of the need for the legislation to comply with “the highest standards of international law”.
He warned: “Without lawful behaviour by the UK, Rwanda would not be able to continue with the Migration and Economic Development Partnership.”
Nick Vineall KC, chair of the Bar Council, said the bill was still “likely to give rise to legal challenges” over planned deportations – pointing out that it “retains the right of the courts to consider whether Rwanda is a safe country for any particular individual”.
In a surprise resignation speech in the Commons on Wednesday, Ms Braverman suggested her own previous ‘stop the boats’ legislation should have been scrapped in favour of a “more robust alternative that excluded international and human rights laws”.
The Tory hardliner also attacked “expansive human rights laws flowing from the European Convention on Human Rights” that were stopping the Rwanda flights.
Ms Braverman also said it was no secret that she supports quitting the ECHR altogether – arguing that a new British human rights law would “finish the job of Brexit by extricating us from a foreign court”.
Ms Braverman’s unusual personal statement to the Commons followed her bitter exit last month. A similar speech by Geoffrey Howe followed his resignation in Commons in 1990, often credited with ending Margaret Thatcher’s political career.
The government claimed the new bill would be “the toughest immigration legislation ever introduced to parliament”, and will “unambiguously exclude the courts from challenging the fact that Rwanda is safe”.
The beleaguered PM insisted that his new legislation would make sure his flagship asylum scheme “cannot be stopped”, as he battles the issue of small boat crossings of the Channel.
Mr Sunak said: “We are taking action to put a stop to it and make clear once and for all that it is parliament that should decide who comes to this country, not criminal gangs”.
The UK’s top court last month blocked the Rwanda policy over concerns that genuine refugees could be wrongly sent back to their countries of origin where they would face persecution.
In an attempt to rectify this, Mr Cleverly signed a new treaty this week which means British judges will preside over a newly established appeals process within Rwanda’s high court for exceptional cases.
Nick Emmerson, president of the Law Society, said the government was “seeking to overturn an evidence-based finding of fact by the Supreme Court and shield itself from accountability under both domestic and international law”.
Former Labour home secretary David Blunkett said the government’s Rwanda deal was “stupid and impractical”. He told The House magazine that Labour should not engage in a “bidding war” with the Tories with undeliverable deportation promises.
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