Sunak said the government had booked commercial charter planes and trained staff to take migrants to Rwanda, a policy he hopes will boost his Conservative Party's flagging fortunes before an election later this year.

The House of Lords had long refused to back the divisive legislation without additional safeguards but eventually relented after Sunak said the government would force parliament to sit as late into Monday night as necessary to get it passed.

"No ifs, no buts. These flights are going to Rwanda," Sunak told a news conference earlier on Monday.

Tens of thousands of migrants, many fleeing wars and poverty in Africa, the Middle East and Asia, have reached Britain in recent years by crossing the English Channel in small boats on risky journeys organised by people-smuggling gangs.

--Reuters--