Rishi Sunak had significant doubts about sending migrants to Rwanda when he was chancellor, papers seen by the BBC suggest.
They suggest Mr Sunak wanted to scale back No 10’s original plans.
They also indicate he was not sure the plan would stop Channel crossings.
And they suggest he was reluctant to fund reception centres to accommodate migrants instead of using hotels or private housing because “hotels are cheaper”.
As prime minister, under pressure from his party, Mr Sunak has made the Rwanda plan one of his top priorities.
The scheme to send some asylum seekers to Rwanda for processing and potentially resettlement, in order to deter people from crossing the English Channel in small boats, was first announced by then-Prime Minister Boris Johnson in April 2022.
Mr Sunak – who became prime minister in October 2022 – was Chancellor of the Exchequer when the Rwanda policy was announced.
The deal has been repeatedly delayed by legal challenges and no asylum seekers have been sent from the UK so far.
The No 10 documents were prepared in March 2022, as Mr Johnson was trying to persuade Mr Sunak to sign off on more funding for the plan. This was shortly before the deal with Rwanda to process migrants was signed.
They suggest Mr Sunak was concerned about the cost of sending asylum seekers to the African country, and wanted to limit the numbers initially.
They say, the “chancellor wants to pursue smaller volumes initially, 500 instead of 1,500” in the first year, and “3,000 instead of 5,000 in years two and three”.
The exact numbers in the eventual plan have never been confirmed, but in April 2022 the BBC saw the accommodation the asylum seekers would be housed it, which were thought to have enough space to process up to 500 people a year, in line with what Mr Sunak seems to have argued for.
The documents describe a significant difference of view between No 10 and 11 Downing Street on the effectiveness of the proposed scheme saying the chancellor believes the “deterrent won’t work”.
Mr Sunak is also described as being reluctant to fund so-called “Greek-style reception centres”, sites where migrants could be housed, rather than being put up in hotels which were said to be costing £3.5m a day at that point, the documents suggest.
They say, the “chancellor is refusing to fund any non-detained accommodation, eg Greek-style reception centres, because hotels are cheaper”.
The documents suggest the Treasury preferred sending migrants to be housed around the country, known as “dispersal”.
The papers also reveal that No 10 suggested Mr Sunak should be told to “consider his popularity with the base” if he was reluctant to sign up to changes to the migration system, including the Rwanda plan.
Despite the proposal being ruled unlawful by the UK Supreme Court, the prime minister has vowed to change the law so that flights can take off to Rwanda.
Yet the revelations about his doubts over the plan are likely to be awkward, especially as some MPs on the right of his party have urged him to go still further to meet his goal of stopping migrants crossing the Channel, potentially leaving the European Convention on Human Rights.
A source close to the prime minister told the BBC: “The prime minister was always fully behind the principle of the scheme as a deterrent.
“As chancellor it was his job to make sure it delivered and taxpayers’ money was appropriately spent.”
A government source said: “As chancellor, Rishi funded the Rwanda scheme and put it at the heart of his 10-point plan the month after becoming PM.
“Now he is passing the Rwanda Bill following the Supreme Court judgment to get flights off the ground. He is the first prime minster ever to oversee a reduction in small boat crossings, which were down by 36% last year.”
In a statement, Labour MP and shadow home secretary Yvette Cooper said: “This shows what an utter con the Tories’ Rwanda scheme is and how weak Rishi Sunak has now become.
BBC