Leading crossbench peer Lord Alton of Liverpool, often called 'the conscience of the House' for his stance on ethical issues, is urging the government to withdraw its Illegal Migration Bill in the wake of the Court of Appeal's Rwanda verdict.
In their ruling, judges determined that Rwanda had not provided enough safeguards to prove it is a "safe third country", meaning it would be unlawful for Britain to send asylum seekers there for their claims to be assessed.
Lord Alton said that peers and MPs on the Joint Committee on Human Rights on which he serves had predicted this would be the likely outcome of the case.
He said the bill which is going through the House of Lords was inconsistent with both domestic and international law: "The best thing the government could do now would be to withdraw the bill, go back to the drawing board, and to try and build a political consensus rather than the toxicity that we have at the moment", he told Premier Christian News.
Prime Minister Rishi Sunak says he "fundamentally disagrees" with the ruling and indicated the government will challenge it in the Supreme Court.
Lord Alton accused the government of what he said "increasingly feels like dog whistle politics", including "stigmatising vulnerable groups of people ". He urged the government to listen to the courts: "My complaint is that there's been no attempt to build a political consensus, quite the reverse."
Home Secretary Suella Braverman claims her Rwanda policy would "smash the business model of the people smuggling gangs", saying she was "determined to deliver, and I won't take a backward step".
David Alton agreed action needed to be taken against the people smugglers. But he was scathing at the Home Secretary's defence of the policy.
"Suella Braverman refused even to appear before the Select Committee that investigated this but we had a 240-page report, taking apart the proposals in the bill", he said. "It was dealt with in the most discourteous way. This isn't a way to make good legislation and is not the way to do politics", he added. "And it's not the way to treat people who are extraordinarily vulnerable".
CAFOD, the international development arm of the Roman Catholic Church in England and Wales, said the legal meaning should cause the government to think again.
"The Illegal Migration Bill represents everything Pope Francis asks us not to be", Aisha Dodwell, head of campaigns for CAFOD, said, "which is why we are urging Catholics to speak out against the Bill and show we are a country that welcomes people who need our help," she added.