The British government watered down parts of its controversial migration bill on Tuesday to try to win Parliament's approval.
The Illegal Immigration Bill, once enacted, would force the authorities to detain and deport people who cross the English Channel by boat.
The Conservative government has vowed to "stop the boats", referring to inflatables and other precarious craft overloaded with migrants crossing from France hoping to live in the UK. More than 45,000 people crossed the channel in 2022; some died trying.
The conservative-majority House of Commons approved the bill, which is met with strong opposition in the House of Lords, whose unelected members can amend but not block a bill.
The lords returned the bill to the commons with 20 amendments removing some of its more stringent provisions.
The government has made some concessions to the opposition: it has eliminated the clause that would apply deportation to people who arrived before the enactment of the law and has reduced from 28 to eight days the time it can detain unaccompanied minors.
But ministers want the commons to strike down most of the lords' amendments before handing the bill back to them, a process called "parliamentary ping-pong".
Immigration Minister Robert Jenrick said the lords should "reconsider" and respect the will of elected lawmakers.
“It is vital that this bill becomes law quickly and in a way that stops the boats,” he said.
The bill denies asylum to unauthorized arrivals and forces them to be detained and deported "to their country of origin or to a safe third country," such as Rwanda. Once deported they would be banned from entering the UK for life.