Britain's interior ministry said it would defend its policy, which is a central part of Prime Minister Rishi Sunak's plan to tackle the record number of migrants arriving in small boats.

The government says the plan will deter people smugglers, though it has been denounced by rights groups and even King Charles since it was announced in April.

The first planned deportation flight was blocked in June last year by a last-minute ruling by the European Court of Human Rights, which imposed an injunction preventing any deportations until the conclusion of legal action in Britain.

Last month, the High Court ruled that it was lawful for Britain to make arrangements with the Rwandan government to send asylum seekers there, but upheld legal challenges brought by eight individual asylum seekers.

Now those asylum seekers plus one other have been granted permission to appeal on various grounds, including that the High Court was wrong to decide the Rwanda removal policy was not "systematically unfair".

Permission was also granted in relation to whether the Home Office was entitled to rely on assurances given by Rwanda about conditions for asylum seekers who are sent to the country.

A spokesperson for the interior ministry, the Home Office, said: "Our ground-breaking migration partnership will relocate anyone who comes to the UK through dangerous and illegal routes to Rwanda, where they will be supported to build a new life.

"This will disrupt the criminal people smuggling gangs who sell lies and put lives at risk.

"The court previously upheld that this policy is lawful and that it complies with the Refugee Convention, and we stand ready to defend this policy at any appeal hearings.”

A lawyer representing charity Asylum Aid, which was also granted permission to appeal against the High Court's ruling, welcomed the decision.

Carolin Ott, from law firm Leigh Day, said in a statement: "Asylum Aid is relieved that the court has rightly recognised there are compelling reasons for its case to be heard in the Court of Appeal."