Rishi Sunak has suffered his heaviest defeat in the House of Lords after the archbishop of Canterbury and former Conservative ministers joined forces with the opposition to force through five amendments to the Rwandan deportation bill.

The string of government setbacks, most passed by unusually large margins of about 100 votes, means the legislation, which aims to clear the way to send asylum seekers on a one-way flight to Kigali, will have to go back to the Commons.

The prime minister has previously warned the unelected chamber against frustrating the “will of the people” by hampering the passage of his safety of Rwanda (asylum and immigration) bill, which has been approved by MPs.