The Government will seek to appeal against a ruling that its plans to deport asylum seekers to Rwanda are unlawful, as Rishi Sunak said he “fundamentally” disagrees with the decision.

In a majority decision on Thursday, judges at the Court of Appeal overturned a High Court ruling that previously said the east African nation could be considered a “safe third country”.

The Court of Appeal’s decision was announced by the Lord Chief Justice Lord Burnett during a short hearing in London, where he stressed the court reached its conclusion on the law and took “no view whatever” about the political merits of the policy.

In a statement, the Prime Minister said: “While I respect the court I fundamentally disagree with their conclusions.

“I strongly believe the Rwandan government has provided the assurances necessary to ensure there is no real risk that asylum-seekers relocated under the Rwanda policy would be wrongly returned to third countries – something that the Lord Chief Justice agrees with.

“Rwanda is a safe country. The High Court agreed. The UNHCR have their own refugee scheme for Libyan refugees in Rwanda. We will now seek permission to appeal this decision to the Supreme Court.

“The policy of this government is very simple, it is this country – and your government – who should decide who comes here, not criminal gangs. And I will do whatever is necessary to make that happen.”

This was echoed by Suella Braverman, who said she was “fully committed” to the policy but also suggested the current system was “rigged against the British people” on the issue.

Asked if she was blaming “lefty lawyers” or “the blob” for the setback, the Home Secretary said: “The system is rigged against the British people, it’s as simple as that.

“It’s why we’re changing the laws through our Illegal Migration Bill, it’s why we’re rolling out a ground-breaking partnership with Rwanda which we believe is lawful, with a country which we believe is safe.

“So, we need to change the system, we need to change our laws, that’s how we’re going to stop the boats.”

Speaking to broadcasters, Ms Braverman said there are “good grounds” for progress on the policy and, despite the ruling, insisted she still had “every confidence” in the plan and that Rwanda was a safe country.

Rwanda policy
The Desir Resort Hotel in Kigali, Rwanda where it is believed migrants from the UK were expected to be taken (Victoria Jones/PA)

Asked whether the Rwanda policy could be toughened up to provide further “assurances” that migrants flown to the country would not be sent back home, the Prime Minister’s official spokesman said: “Yes, so obviously this is a very detailed judgment and the Lord Chief Justice dissents with other judges.

“We need to go through that carefully and consider what if anything if is appropriate in our approach. Obviously some of these issues we’d want to put before the Supreme Court should we be given permission to do that. I’m not going to pre-empt that.”

Downing Street refused to say whether it still believes any migrants will be sent to Rwanda before the next election.

The Rwandan Government said it took “issue” with the Court of Appeal’s ruling and insisted the east African nation was “one of the safest countries in the world”.

In his summary of the court’s decision, Lord Burnett said there was a “deliberately tight timetable” to decide the consequences of the ruling, in part so any bid to for the go-ahead for a Supreme Court challenge “can be decided promptly”.

In the 161-page ruling following the appeal in April, Sir Geoffrey Vos and Lord Justice Underhill concluded that deficiencies in the asylum system in Rwanda mean there is a “real risk” asylum seekers could be returned to their home country and face persecution or other inhumane treatment when they may have a good claim for asylum.

Sir Geoffrey continued: “In practice, Rwanda can only deliver on its good faith assurances if it has control mechanisms and systems in place to enable it to do so.

“Both history and the current situation demonstrate that those mechanisms have not yet been delivered. They may in the future be delivered but they are not, on the evidence, there now.”

The judge added: “Our conclusion on the safety of Rwanda issue means that the Rwanda policy must be declared unlawful.”

Ms Braverman is expected to make a statement in the House of Commons later on Thursday, while Labour said the decision shows that the Government’s plan to stop small boats crossings is “completely unravelling”.

Sir Keir Starmer slammed the policy as a “headline-grabbing gimmick”, telling the PA news agency during a visit to Selby, North Yorkshire: “What the court’s judgment shows is they’ve spent that £140 million of taxpayers’ money without even doing the basics to see whether the scheme was really fit for purpose.”

His deputy, Angela Rayner, said: “We’ve had more Conservative home secretaries in Rwanda than we’ve had asylum seekers sent there.”

Meanwhile shadow home secretary Yvette Cooper described the Rwanda policy as “unworkable, unethical and extortionate, a costly and damaging distraction from the urgent action the Government should be taking”.

The Court of Appeal’s ruling is the latest setback in Rishi Sunak’s efforts to “stop the boats” – one of his flagship policy pledges.

So far this year 11,279 people have been detected making the trip, according to provisional Home Office figures, while the Government’s Illegal Migration Bill aimed at beefing up powers to tackle the problem has suffered a series of defeats during its passage through the House of Lords.

The flagship legislation, which has already been passed by the Commons, saw four Government defeats in the Lords on Wednesday.

Thursday’s judgment also comes days after the Home Office’s own figures showed the Government could spend £169,000 on every asylum seeker forcibly removed to a third country such as Rwanda.

Nearly two in five people would need to be deterred from crossing the Channel in small boats for the the Illegal Migration Bill to break even, the economic impact assessment published on Monday said.

The £169,000 cost includes flights and detention, as well as a £105,000 per person payment to third countries, though the the sum is an estimate not based on the true cost of the “commercially sensitive” Rwanda scheme.

Campaigners welcomed the appeal ruling, with charity Asylum Aid, which brought the challenge alongside several asylum seekers, describing the decision as a “vindication of the importance of the Rule of Law and basic fairness when fundamental rights are at stake”.