The flagship Rwanda asylum plan is not the “be all and end all” of government efforts to tackle illegal migration, the Home Secretary has said.

Prime Minister Rishi Sunak remains under pressure to revive the policy after this month’s Supreme Court defeat, with some Tory MPs also angered by latest data on legal net migration showing a record number of arrivals last year.

James Cleverly, who replaced a sacked Suella Braverman as Home Secretary in Mr Sunak’s reshuffle, has admitted being frustrated at the focus on the Rwanda policy.

“My frustration is that we have allowed the narrative to be created that this was the be all and end all,” he told The Times.

“The mission is to stop the boats. That’s the promise to the British people. Never lose sight of the mission.

“There are multiple methods. Don’t fixate on the methods. Focus on the mission.”

The senior Cabinet minister also made clear his reservations about any move to leave the European Convention on Human Rights (ECHR), which is advocated by Tory right-wingers who see it as a major barrier to ending Channel crossings.

Mr Sunak has pledged not to let a “foreign court” stop flights to Rwanda, with plans for a new treaty and emergency legislation to ensure the plan is legally watertight.

It was the UK Supreme Court, rather than “a foreign court”, that dealt the latest blow to the government’s hopes of sending asylum seekers who arrive in the UK on a one-way trip to Rwanda.

But Tories are keen to ensure that the ECHR and the Strasbourg court that rules on it will not prevent the policy – first announced in 2020 – from being implemented.

The new Home Secretary’s stance appears to differ from his predecessor, who made clear her frustrations with the ECHR.

“My argument has always been that we need to modernise, update and reform,” Mr Cleverly said.

“What some people, I fear, do is jump to their preferred solution and hang on to that really, really tightly and say this cannot be the right answer unless you do a particular thing.

“I do not want to do anything that might undermine the key co-operation we have with countries [who] are very wedded to the ECHR for understandable reasons.

“Nothing is cost free. Everything needs to be considered, the advantages and disadvantages.”

It came as Boris Johnson became the latest Tory to pile pressure on Mr Sunak to act on immigration.

Net migration into the UK peaked at 745,000 in the year to December 2022, which is a record, according to revised estimates published by the Office for National Statistics (ONS) on Thursday.

The data places migration levels at three times higher than before Brexit, despite a Conservative Party 2019 manifesto pledge to bring overall numbers down.

Many MPs on the right of the party have called on Mr Sunak to honour that commitment.

Former prime minister Mr Johnson added his voice to those urging reform of the immigration system, as he echoed Mrs Braverman in calling for an increase in the minimum salary threshold for UK visas.

Writing in his Daily Mail column, Mr Johnson said: “You will remember that after Brexit everyone was wailing about the thought of EU workers fleeing Britain, and business was worried about shortages. So the Migration Advisory Committee put the ­minimum at only £26,000 — not much more than the living wage.”

He said that figure was “way too low”.

“The minimum income for most types of migrant worker coming to the UK should now go right up to £40,000 or more — because it is the right thing for migrant workers, and for the entire British workforce,” he added.

“We have the powers to sort it out, and to change our immigration rules — which is exactly why the British people voted to take back those powers in 2016. We can do it now.”

Mr Johnson, who led the party to victory with the 2019 manifesto, only left office last year. The election-winning campaign saw the Tories pledge that “overall numbers will come down” and “we will ensure that the British people are always in control”.

Immigration minister Robert Jenrick is understood to have worked up a plan designed to appease calls from right-wing Tories for the government to take action.

He is pushing for a ban on foreign social care workers from bringing in any dependants and a cap on the total number of NHS and social care visas.

His plan would also scrap the shortage occupation list, a programme that allows foreign workers to be paid 20% below the going rate in roles that suffer from a lack of skilled staff.

Other data released by the ONS this week indicated that net migration for 2023, up until June, was 672,000.

The figures suggest a total of 1.279 million more people have come to the UK than have left the country during the past two years.

PA – Dominic McGrath and Patrick Daly