Foreign Secretary Lord Cameron is urging his fellow peers to get behind the Rwanda asylum plan after the scheme suffered its first defeat in the upper chamber.
The House of Lords backed by a majority of 43 an unprecedented move seeking to delay a treaty with the east African nation that is intended to make the policy legally watertight.
Further battles with peers are expected when the domestic legislation underpinning the deal to send some asylum seekers on a one-way trip to Rwanda is debated in the Lords next week.
Prime Minister Rishi Sunak has warned the unelected House not to block the “will of the people” when the Safety of Rwanda (Asylum and Immigration) Bill is debated.
And Foreign Secretary Lord Cameron said: “What the Government will do is, having passed the Bill through the House of Commons, bring the Bill to the House of Lords, and I’ll be urging fellow peers in the House of Lords to vote for that Bill because it’s absolutely essential that we stop the boats and that we fulfil the Prime Minister’s plan.
“It’s not acceptable to have people travelling from a perfectly safe country – France – to another safe country – Britain – and to be able to stay, and that’s what the Rwanda plan is all about and why I urge the House of Lords to pass this Bill.”
On Monday peers supported a call by the Lords International Agreements Committee (IAC) that Parliament should not ratify the treaty until ministers can show Rwanda is safe.
The Government agreed the legally-binding treaty with Kigali in December, saying it addressed concerns raised by the Supreme Court about the possibility of asylum seekers deported to Rwanda then being transferred to a country where they could be at risk.
But the cross-party committee said promised safeguards in the agreement are “incomplete” and must be implemented before it can be endorsed.
Unlike the Commons, which has the power to delay ratification of a treaty, the Lords can only advise.
However, ignoring the demand by peers could later be used in a legal challenge against the Government.
Just one Conservative peer – the Earl of Dundee – voted with Labour, the Liberal Democrats and dozens of crossbench peers for the motion to delay ratification.