Rishi Sunak’s plan to deport people seeking asylum to Rwanda has been ruled unlawful by the Supreme Court. 

It leaves his pledge to "stop the boats" in tatters. 

The five judges upheld an appeal court ruling which found that there was a real risk of deported refugees having their claims wrongly assessed or being returned to their country of origin where they faced persecution or inhumane treatment in breach of Article 3 of the European Convention on Human Rights (ECHR).

The judgement looks set to trigger a furious internal battle in the Conservative party.

It follows an explosive letter from Suella Braverman, released on Tuesday, which suggested the Prime Minister had reneged on a deal to legislate to disapply the European Convention on Human Rights.

According to reports, No 10 believes that the backlash is confined to only a handful of supporters, but some of the ex-minister's allies think that as many as 60 MPs are ready to back her rebellion.

READ MORE: Braverman uses stinging letter to tell Sunak he's 'failed to deliver'

The Rwanda policy was first announced by Boris Johnson back in April 2020, but not a single migrant has been removed to Kigali after a series of legal challenges.

The plan was to give those who the UK believed had arrived illegally a one-way ticket to Rwanda.

The African country would initially receive a £120m payment and then money for each migrant processed. 

The government hoped the plan would deter people from crossing the Channel in small boats.

Lord Reed, the President of the Supreme Court, said in a summary of the ruling that the five justices were unanimous in their decision.

He said the “legal test” in the case was whether there were “substantial grounds” for believing that asylum seekers sent to Rwanda would be at “real risk” of being sent back to the countries they came from where they could face “ill-treatment”.

The judge added: “In the light of the evidence which I have summarised, the Court of Appeal concluded that there were such grounds.

“We are unanimously of the view that they were entitled to reach that conclusion. Indeed, having been taken through the evidence ourselves, we agree with their conclusion.”

He said there was a legal rule that “refugees must not be returned to their countries of origin, either directly or indirectly, if their life or freedom would be threatened in that country”.

“That rule is called the principle of non-refoulement,” he said.

He added: “We accept the Home Secretary’s submission that the Rwandan government entered into the agreement in good faith and that the capacity of the Rwandan system to produce accurate and fair decisions can and will be built up.

“Nevertheless, asking ourselves whether there were substantial grounds for believing that a real risk of refoulement existed at the relevant time, we have concluded that there were.

“The changes needed to eliminate the risk of refoulement may be delivered in the future, but they have not been shown to be in place now.”

READ MORE: Minister defends 'eye-watering' cost of 'immoral' Rwanda deportation plan

Lord Reed said that the European Convention on Human Rights was not the only international treaty that was relevant to the Rwanda case.

He added: “There are other international treaties which also prohibit the return of asylum seekers to their countries of origin without a proper examination of their claims.”

These included the United Nations (UN) Refugee Convention, the UN Convention against Torture and Other Cruel, Inhuman or Degrading Treatment and the UN International Covenant on Civil and Political Rights, he said.

Rishi Sunak will hold a Downing Street press conference later on Wednesday to address the ruling.

He said: “We have seen today’s judgment and will now consider next steps.

“This was not the outcome we wanted, but we have spent the last few months planning for all eventualities and we remain completely committed to stopping the boats.

“Crucially, the Supreme Court – like the Court of Appeal and the High Court before it – has confirmed that the principle of sending illegal migrants to a safe third country for processing is lawful. This confirms the Government’s clear view from the outset.

“Illegal migration destroys lives and costs British taxpayers millions of pounds a year. We need to end it and we will do whatever it takes to do so.

“Because when people know that if they come here illegally, they won’t get to stay then they will stop coming altogether, and we will stop the boats.”

READ MORE: Auditors register 'significant uncertainty' on Ferguson Marine future

Taking to X, formerly Twitter, Humza Yousaf said: “Not only is the UK Govt’s policy of sending asylum seekers to Rwanda morally repugnant, but it has now been confirmed as unlawful too.

“The policy must be scrapped.

“We need a humane system that doesn’t leave asylum seekers stuck in destitution for years without the right to work.”

The Liberal Democrats said it was time for Home Secretary James Cleverly to “get on with fixing the broken asylum system.”

Alistair Carmichael, the party’s home affairs spokesman, said: “It was clear from the get-go that the Conservatives’ Rwanda scheme was destined to fail.

“Not only is it immoral, unworkable and incredibly costly for taxpayers — but the Supreme Court has confirmed that it is unlawful too."

Scottish Green MSP. Maggie Chapman said the plan was "vile and racist."

“This scheme may have been blocked, but it didn't happen in isolation. We need to dismantle the anti-immigrant policies and the hostile environment that has endured for far too long," she added.

Steve Smith, CEO of refugee charity Care4Calais, who were a claimant in the initial legal challenge, welcomed the judgement, calling it a "victory for humanity."

"This grubby, cash-for-people deal was always cruel and immoral but, most importantly, it is unlawful," he added.

Amnesty International said the Government must now focus on tackling the backlog of asylum claims.

Currently, there are 33,253 "legacy" cases still to be processed.

They are defined as application received before June 28 2022.

The Government has pledged to clear the legacy backlog by the end of this year.

Sacha Deshmukh, Amnesty's chief executive in the UK, said: “The deal with Rwanda – a country with a track record of serious human rights violations, including arbitrary detention, torture and the repression of free speech – was massively ill-conceived and cruel."