So-called “notwithstanding clauses” would allow British courts to ignore ECHR rulings in specific cases, such as when an illegal migrant requests to remain in the UK to preserve their right to a family life.
However, Mr Sunak has not made that move and declined to back pulling the UK out of the ECHR – something Mrs Braverman has supported in the past and is likely to champion from the back benches.
Mrs Braverman wrote that she had repeatedly warned the Prime Minister that his Rwanda policy faced defeat in the Supreme Court. She also said that, even if the judges allow the Rwanda flights to go ahead, the legislation for tackling illegal migration would not prove effective.
“At every stage of litigation I cautioned you and your team against assuming we would win,” she wrote. “I repeatedly urged you to take legislative measures that would better secure us against the possibility of defeat.
“You ignored these arguments. You opted instead for wishful thinking as a comfort blanket to avoid having to make hard choices. This irresponsibility has wasted time and left the country in an impossible position.
“If we lose in the Supreme Court, an outcome that I have consistently argued we must be prepared for, you will have wasted a year and an Act of Parliament, only to arrive back at square one. Worse than this, your magical thinking – believing that you can will your way through this without upsetting polite opinion – has meant you have failed to prepare any sort of credible ‘Plan B’.”