Britain's revived plan to send asylum seekers to Rwanda would drastically strip back courts' ability to scrutinise decisions and risks dealing a "serious blow to human rights", the United Nations rights chief said on Monday.
Prime Minister Rishi Sunak is pushing legislation through parliament that would declare Rwanda a safe country for asylum seekers despite misgivings from some lawmakers, who have attacked the plan as unethical and unworkable.
Under the proposals, asylum seekers who arrive on England's southern coast in small, inflatable boats would be sent to Rwanda to live.
Volker Turk said the current state of the bill, which has yet to pass the House of Lords, would require Rwanda being treated as a "safe country" regardless of the evidence.
"You cannot legislate facts out of existence," said Turk, saying British courts had a proven track record of making these decisions thoroughly in the past and should continue to do so.
"It is deeply concerning to carve out one group of people, or people in one particular situation, from the equal protection of the law," he added.
With his Conservative Party trailing in the opinion polls before an election expected later this year, Sunak has invested large amounts of political capital in the Rwanda policy in the hope it will allow him to meet a promise to "stop the boats".
More than 1,300 asylum seekers have arrived in Britain on small boats so far this year.
