Leaked documents from March 2022 seen by Sky News - created shortly before the policy was first announced by Boris Johnson - suggested Mr Sunak wanted it scaled back.

The documents state the “chancellor wants to pursue smaller volumes initially” of people being sent to Rwanda with “500 instead of 1.5k this year, and 3k instead of 5k, in years two or three”. Other papers from 2022 suggest Mr Sunak thought the “deterrent won’t work” and there would be more boat crossings in the summer.

But speaking to the BBC on Sunday, the prime minister restated his backing of the scheme and said he was just scrutinising the proposals in their early form. He said: “My job [was] to ask probing questions of every proposal that crossed my desk as chancellor.”Whether you have doubts about it or not, you shouldn’t come to it with a preconceived notion that everything is fine when you are spending taxpayers’ money, of course you shouldn’t.

“You should always ask probing questions, you should always approach things from a position of scepticism to ensure that you get value for money for taxpayers.”That is the job of the chancellor and the Treasury when things crossed their desk.

“But to infer from that that I don’t believe in the scheme or the principle of deterrence is wrong. I was doing my job to get good value for money for taxpayers.”I went through that process, funded the scheme with the prime minister and, as prime minister myself, I have made sure that we have a similar deterrent working with Albania, and I have made the point that it is because Albania is working that we should have confidence that the Rwanda scheme will work too.“The leaked documents summarised Mr Sunak’s position in early 2022 as”refusing to fund any non-detained accommodation (eg Greek-style reception centres) because hotels are cheaper".

The papers suggest Mr Sunak was instead in favour of increasing the “dispersal of people out of hotels into private sector accommodation” around the country - and noted this might not be popular with Conservative voters.

Mr Sunak managed to see off a potential rebellion on the Safety of Rwanda Bill from his backbenches at the end of last year but is facing fresh pressure from Tory MPs who say it does not go far enough to address their concerns.

Robert Jenrick, who resigned as immigration minister because he thought Mr Sunak’s stance was not hard enough, is one of those looking to force the prime minister’s hand.

According to The Sunday Times, Mr Jenrick is looking to table two amendments to the Rwanda plan - one to prevent individual appeals from people who think they would not be safe in the country, and a second to enforce a law that the government could ignore so-called “rule 39” orders from the European Court of Human Rights (ECtHR) in Strasbourg which have been used to stop flights.

As currently written, the Safety of Rwanda Bill states that the power to ignore those decisions rests with ministers, and UK courts should not take them into account for decision-making.

But when asked if he would ignore such an order from the ECtHR by the BBC, Mr Sunak would not say definitively, instead saying that “there’s lots of steps between now and then”

He added: “I’m actually entirely confident that what we’re doing is compliant with all our international obligations. But I’ve been crystal clear. I won’t let a foreign court block our ability to remove people safely to Rwanda if we get to that point.”