Former immigration minister Robert Jenrick said he is prepared to put forward changes to the Prime Minister’s Rwanda legislation to ensure it is “sufficiently robust”.

Mr Jenrick said he plans to “lay amendments to the Bill next week” if Rishi Sunak has not strengthened it since it last appeared before MPs.

The Safety of Rwanda legislation is due to return to the House of Commons this month as Rishi Sunak looks to overcome legal hurdles to his flagship immigration policy.

Conservative Party leader Mr Sunak has said he wants to have deportation flights taking migrants to Kigali by the spring, following his pledge 12 months ago to stop boats of migrants from crossing the English Channel.

I don’t think that the Bill that is going through Parliament is sufficient

The Bill passed at second reading with a healthy majority of 44 votes during its first Commons test last month.

But Mr Jenrick and sacked home secretary Suella Braverman were among a tranche of high-profile Conservative MPs to abstain on the vote, with hardline right-wing Tory factions threatening to vote down the Bill next time if it is not tightened.

Mr Jenrick, once seen as a close ally of Mr Sunak, quit his Home Office role in December following the publication of the Rwanda Bill, arguing that the draft law “will not succeed” in its current guise.

The Bill compels judges to treat Rwanda as a safe country after the Supreme Court ruled the scheme was unlawful over risks to refugees.

The legislation, if approved by Parliament, gives ministers the powers to disregard sections of the Human Rights Act.

But it does not go as far as allowing the UK Government to dismiss the European Convention on Human Rights, as hardliners have demanded.

Mr Jenrick, speaking to Sky News on Saturday, said: “I don’t think that the Bill that is going through Parliament is sufficient.

“If we say we are going to do whatever it takes (to stop the boats), we have to do whatever it takes and that means strengthening that Bill.”

The Newark MP added: “I hope that he (Rishi Sunak) will strengthen the Bill that is coming through Parliament.

“And I have been very clear that if he doesn’t do that, then I will lay amendments to the Bill next week to make sure that it is the piece of legislation necessary, that it is sufficiently robust to do the job that the British public expect.”

The threat of changes to the legislation from the right follows reports that Mr Sunak had doubts when he was chancellor over whether the Rwanda scheme would stop Channel crossings.

The BBC said it had seen No 10 papers from March 2022, a month before the concept was announced by then prime minister Boris Johnson, which showed that Mr Sunak was not convinced of the plan’s effectiveness.

The documents suggest Mr Sunak felt “hotels are cheaper” than reception centres to house migrants and that he was also concerned about the cost of sending asylum seekers to Africa and wanted to limit the numbers.

The corporation said the documents revealed the “chancellor wants to pursue smaller volumes initially” with 500 flown to Rwanda in the first year of the scheme, instead of the proposed 1,500.

He then proposed “3,000 instead of 5,000 in years two and three”, according to the report.

Mr Sunak is described as believing the “deterrent won’t work”.

Downing Street this week refused to endorse comments made by Home Secretary James Cleverly, who replaced Mrs Braverman, after the Cabinet minister told LBC he wanted to see all migrant boat crossings stopped by the end of the year.

The Prime Minister’s official spokesman said he was “not going to set out a deadline” but repeated Mr Sunak’s commitment to wanting the first removals to take place by the spring.