"Even if the UK-Rwanda deal and the Rwanda Nationality and Borders Bill are passed, airlines and aviation regulators could be complicit in violating internationally protected human rights and court rulings by facilitating removals to Rwanda," the experts said in a statement.

They also said that sending asylum seekers to Rwanda, or any other country where they face a real risk of persecution, would violate the prohibition against torture and other cruel and inhuman treatment.

In November 2023, the UK Supreme Court ruled that transfers to Rwanda would violate Article 3 of the European Convention on Human Rights, which prohibits torture or inhuman or degrading treatment or punishment.

"If airlines and aviation authorities comply with State decisions that violate human rights, they must be held accountable for their conduct," they said.

"As the UN Guiding Principles on Business and Human Rights emphasize, aviation regulators, international organizations and business actors have a responsibility to respect human rights," they added.

UN Guiding Principle 13 prohibits businesses from contributing to human rights abuses and Guiding Principle 23 requires businesses to comply with all applicable laws, respect internationally recognized human rights, and address the risk of contributing to serious human rights abuses as a matter of due diligence wherever they operate, the press release said.

The UN experts have been engaging with the UK Government, as well as national, European and international aviation regulatory bodies, including the UK Civil Aviation Authority (CAA), the European Union Aviation Safety Agency (EASA), and international actors, including the International Air Transport Association (IATA) and the International Civil Aviation Organization (ICAO), to raise their concerns and remind them of their responsibilities, it said.

"Previous UN expert engagement on related issues includes a communication on the UK-Rwanda deal, a press release on a letter regarding the draft legislation, and an intervention before the Court of Appeal," it added.

However, UK Prime Minister Rishi Sunak said on Tuesday that the first deportation flights of migrants to Rwanda could take place within 10 to 12 weeks.

Sunak told a news conference that parliament would sit this evening "as long as it takes" to get the legislation through, blaming the opposition Labour Party for holding up the process.

The legislation is due to return to the House of Commons after peers in the House of Lords last week thwarted the government's attempt to pass the bill by voting through two amendments.

"Once the legislation is passed, we will start the process of removing those who are identified for the first flight," Sunak said. 

There were 29,437 illegal migrant arrivals in small boats such as dinghies in 2023, down from 45,774 in 2022.