UN experts have warned commercial airlines against cooperating with deportation flights to Rwanda – saying they could fall foul of international law.

A bill to smash legal barriers preventing asylum seekers from being sent to the African country is expected to pass later today, though Parliament could sit until late into the night as MPs are expected to do battle with the Lords on amendments.

Lords amendments include measures to prevent asylum seekers who assisted the UK Government in Afghanistan from being deported.

READ MORE: Rishi Sunak urges Lords to back Rwanda plan ahead of final vote

While the legislation is expected to pass, the UK Government still faces the hurdle of finding companies willing to charter the flights.

And UN experts have piled pressure on commercial firms who may be considering taking Government contracts for deportation flights – warning them that they may find themselves “complicit in violating internationally protected human rights and court orders”.

Siobhán Mullally, a special rapporteur on human trafficking trafficking, Gehad Madi, a special rapporteur on migrants’ rights and Allice Jill Edwards, the special rapporteur on torture, issued the statement ahead of voting in Parliament on Monday.

They said: “If airlines and aviation authorities give effect to State decisions that violate human rights, they must be held responsible for their conduct.

“As the UN Guiding Principles on Business and Human Rights underline, aviation regulators, international organisations and business actors are required to respect human rights.”

During a press conference on Monday morning, Prime Minister Rishi Sunak said there was an airfield “on stand-by”, commercial charter planes had been booked “for specific slots” and 500 “highly-trained individuals” were ready to escort illegal migrants all the way to Rwanda, with 300 more expected to be trained in the coming weeks.

There has been widespread speculation that the Home Office has found it difficult to find a commercial partner to carry asylum seekers, because of the controversy surrounding the scheme.

But the Daily Express on Monday reported flights had already been booked, suggesting the Government has found a willing contractor. 

The paper also reported that the Government has discussed flights beginning in June, though the Prime Minister said today he expected them to start in 10 to 12 weeks, which would mean either the beginning or middle of July.