Lord Cameron has threatened to get tough on European human rights judges if they move to thwart the Government’s Rwanda plan.
The Foreign Secretary sought on Monday to reassure anxious Tory MPs of his stance on the controversial European Court of Human Rights (ECHR).
Sources said he stressed the importance of pushing on with Rishi Sunak’s new plan for emergency legislation and a new treaty - and then take on Strasbourg if required.
His comments came as he faced the 1922 backbench committee of MPs. Sources said the former Prime Minister insisted he had first-hand experience with the ECHR and understood the need to curtail its powers.
Lord Cameron cited his own battle in stripping prisoners of voting rights, an ECHR red line that he continued to defy during his time at No 10. He even slapped down suggestions last week by his former chancellor George Osborne that leaving the ECHR - demanded by some Tories - was off the table.
Mr Sunak has insisted he will do “whatever is necessary” to secure migrant deportation flights to Rwanda as he considers whether to opt out of human rights laws.
On Monday, the Prime Minister again said he would not let “a foreign court” prevent migrants being removed from the UK and pledged to end the legal “merry-go-round” that has blocked the Rwanda flights since last summer.
Mr Sunak was responding to questions about proposals to opt out of domestic and international human rights laws to secure the flights.
The PM has committed to emergency legislation and a new treaty to declare Rwanda safe after the Supreme Court last week ruled the Rwanda policy unlawful because it was unsafe for asylum seekers to be deported there by the UK.
But he is also considering two further options to restrict the ability of illegal migrants to block their deportations to Rwanda.
One would disapply the Human Rights Act in asylum claims to prevent courts from blocking flights. This would force a claimant to take their case to the European Court of Human Rights, a process that would take time during which advocates of the Rwanda policy hope it could be shown to have worked.
Under a second option, ministers would remove the right of judicial review and include “notwithstanding” clauses that would allow ministers to ignore the European Convention on Human Rights without leaving the treaty.
Robert Jenrick, the immigration minister, is pushing for both options as a “belt and braces” approach to the emergency legislation, which will bar anyone from lodging a legal challenge against the policy as a whole but not prevent individuals bringing cases against their deportation.
It is thought at least half a dozen Cabinet ministers would support such a move, which would divide the Cabinet.
James Cleverly, the Home Secretary, has previously declared his opposition to quitting the convention and said last week he did not believe it would be necessary to quit human rights laws to realise the Rwanda plan.
It is understood that Victoria Prentis, the Attorney General, a strong supporter of the convention, has indicated that she would not oppose opting out of the human rights laws on solely ideological grounds but was more concerned about the practical implications.
She is concerned that major carve-outs from human rights legislation could make it impossible to get the legislation through the Lords, or at the very least lead to substantial delays.
Alex Chalk, the Justice Secretary, another strong supporter of the European Convention on Human Rights, is said to want legislation that will deliver the policy without necessarily being hamstrung by “high ideals” and is “waiting to see what form it will take”.
Speaking at a college in Enfield, north London, on Monday, Mr Sunak said: “I’m completely committed to doing what is necessary to get those flights off and that scheme up and running. Because we have prepared for all circumstances, we have been working on a new treaty with Rwanda that will address all the concerns that were raised by the Supreme Court.
“We will combine that with new emergency legislation that will make it crystal clear – and give Parliament the opportunity to confirm – that Rwanda for all of these purposes is a safe place to implement our scheme.
“And I won’t let a foreign court stop us from getting flights off to Rwanda. This is a reasonable country. This is a reasonable Government. But people’s patience has run thin, and we have got to end this merry-go-round. And that is what I am determined to do.”