Sunak’s hardline immigration plan includes a cap on refugees and floating detention centres for asylum seekers

The former chancellor would withhold aid from poor countries that refused to cooperate

Rishi Sunak has sparked outrage as he set out a hardline plan to deal with immigration if he becomes prime minister. The package features a cap on annual refugee numbers and the withholding of aid from some of the world’s poorest countries if they refuse to take back failed asylum seekers.

The former chancellor, who is trailing Liz Truss in polls of Conservative Party members in the current leadership election, said he would ramp up the controversial plan to operate deportation flights to Rwanda and that he would seek to establish similar schemes with other countries.

And he said he would bar anyone arriving by small boat across the Channel from remaining in the UK – despite the fact that the majority of unauthorised arrivals are currently awarded asylum status.

Meanwhile, Ms Truss has also doubled down on support for the controversial plan, calling it the “right” policy and indicating she could extend the scheme further.

“I’m determined to see it through to full implementation, as well as exploring other countries that we can work on similar partnerships with. It’s the right thing to do,” she told the Mail on Sunday.

“I’m also determined to make sure that we have the right level of forces at our border. I’m going to increase the border force to make sure that we have the proper protection in place directly at the border.”

Mr Sunak’s plans were branded “cruel” by aid charity Oxfam, whose head of government relations Sam Nadel said: “If anything, this shows that the heat of campaigning leads to bad policy. If the former chancellor wins this race, he will be more than a party leader, he will be prime minister and a world leader.

"To meet a world in desperate crisis - facing climate change, famine and conflict - with cruel policies such as these would not live up to the role. We need more aid and safe and legal routes to the UK.”

Mr Sunak, who admits he is the underdog in the race to succeed Boris Johnson, declared on Saturday that “illegal immigration” was one of five national emergencies that would require him to put the UK on a “crisis footing” as soon as he took office.

His “10-point plan to stop illegal immigration” is significantly more hardline than the measures contained in the Nationality and Borders Act that was put into law by Priti Patel earlier this year.

It will put him on course for a clash with the European Court of Human Rights by narrowing the definition of who qualifies for asylum in the UK, as well as giving authorities additional powers to tag, detain and monitor incomers.

And it will put him on a collision course with aid charities by explicitly linking humanitarian support with cooperation on immigration – something Christian Aid has described as “beyond the pale”.

States that fail to take back nationals who have committed offences or been denied the right to stay in the UK – as Eritrea, Iraq and Sudan are currently understood to do – would be denied access to British aid and subjected to retaliatory trade and visa measures.

Mr Sunak – whose own grandparents arrived in the UK from India as legal migrants – would introduce a cap, set annually by parliament, on the number of refugees to be accepted by “safe and legal routes”, while ensuring that others are removed from the country.

Effectively barring the way to remaining in Britain for those entering the country by unauthorised routes, his plan states: “The only route to asylum in the UK will be a safe and legal route.”

A military-led Small Boats Taskforce, backed by investment in surveillance technology, would be given the resources and authority needed to “end small boat beach landings” and oversee the detention and removal of those crossing the Channel in dinghies.

Adapted cruise ships would be used as floating detention camps for migrants deemed to have arrived in the UK illegally, in a bid to rein in the £5m-a-day cost of housing them in hotels.

Mr Sunak would seek an urgent meeting with French president Emmanuel Macron in an effort to “hold the French to account”, with clear targets on stopping boats and “no options off the table”.

He promised to do “whatever it takes” to implement and scale up the agreement with Rwanda, under which the African country is paid to accept asylum seekers without their claims ever having been considered in the UK. And he said he would pursue similar arrangements with other states.

Meanwhile, penalties on businesses using illegal migrant labour would be toughened, and Mr Sunak would set a target of resolving 80 per cent of asylum claims within six months in order to reduce the current backlog of more than 100,000 applications awaiting an initial decision.

Mr Sunak, who supported Brexit, said his “reasonable, fair and proportionate” package would enable him to fulfil the Leave campaign’s promise to “take back control of our borders”.

“Right now the system is chaotic, with law-abiding citizens seeing boats full of illegal immigrants coming from the safe country of France, with our sailors and coastguards seemingly powerless to stop them,” he said. “It must stop, and if I am prime minister I will stop it.”

But Refugee Council CEO Enver Solomon urged both candidates in the Tory leadership race to “take a new direction” and to ditch the Rwanda scheme in favour of safe routes and humanitarian visas.

“Whoever becomes our next prime minister must replace our broken asylum system with a system that is fair, humane and orderly,” said Mr Solomon.

“This is an opportunity to commit to increasing safe routes, such as family reunion and humanitarian visas, so that those at risk of violence and persecution do not have to make dangerous journeys to find safety here. We urge our next prime minister to take a new direction and abandon the cruel Rwanda scheme.”

Pete Moorey, head of campaigns and UK advocacy at Christian Aid, condemned the proposed linkage of migration and aid.

“At a time when conflict and the climate crisis are pushing more people into poverty in East Africa and many other parts of the world, any proposal that further shrinks our financial support is beyond the pale,” he said. “The UK has a historic and moral responsibility to ending extreme poverty. We should be leading the world in tackling the interlocking global crises of hunger, climate, and conflict. That is what leadership looks like."

Shadow home secretary Yvette Cooper said: “Rishi Sunak as chancellor of the Exchequer, and Liz Truss as foreign secretary, signed off the Rwanda deal – writing off £120m of taxpayers’ money on an unworkable scheme that the government has admitted is unenforceable with a very high risk of fraud.

“They have been responsible for wasting taxpayers’ money, and have served in the cabinet that has totally failed to stop the criminal gangs or sort out the asylum system.

“The Conservatives have been in power for 12 years. It beggars belief that they claim to be the ones to sort things out when they have both failed for so long.”

Liberal Democrat home affairs spokesperson Alistair Carmichael said that Mr Sunak should never be forgiven for signing off “ridiculous amounts” of taxpayers’ money on the Rwanda scheme, which has so far resulted in no deportations and which the Kigali government now says has the capacity for only 200 people.

“These are people who should have been treated with the decency and respect they deserve, but Rishi Sunak wasted the public’s money to send them far away,” said Mr Carmichael. “He does not represent Britain’s long and proud history of helping those fleeing war and persecution.”