Rishi Sunak's flagship proposals to tackle boats crossing the Channel suffered a brutal mauling last night as peers inflicted 11 defeats in one day.
The onslaught in the upper chamber came as the Prime Minister faced a challenge to his authority with Tory MPs calling for more severe action on immigration.
On Monday evening peers demanded a series of changes to the Illegal Migration Bill - the Prime Minister's attempt to detain and remove those who arrive in the UK without permission.
The Lords voted for changes on the strict time limits on the detention of children and pregnant women, protections for modern slavery victims, and safeguards for unaccompanied youngsters.
Other revisions backed by the unelected chamber would place restrictions on removal destinations for LGBT+ people and strip out curbs on legal challenges to deportation.
The latest defeats will fuel the prospect of a prolonged and bitter tussle between the Government and the Lords during so-called parliamentary ping-pong.
The bitter setback comes as the Prime Minister marks six months to the day since setting out his five key pledges to the British public - without a single one being met.
Alongside the Lords defeats one of the key commitments - to "stop the boats" - suffered a blow yesterday after it was revealed Channel crossings reached a new record for the month.
Provisional figures showed more than 11,000 asylum seekers had so far made the dangerous Channel crossing this year, with a record for June of 3,824.
And just last week the Government's highly controversial plan to deport asylum seekers to Rwanda was ruled unlawful by the Court of Appeal.
The Government now intends to overturn the judgement at the Supreme Court - but the move decreases the likelihood of deportation flights taking off any time soon.
Speaking to BBC Radio 4's Today programme the crossbench peer Lord Alex Carlile said: "The Bill should be dead because the purpose of the Bill is dead.
"We were told this Bill would stop the boats - it hasn't stopped the boats."
Referring to the court defeat, he added: "This whole Bill has no purpose left at the moment and what the Government really should have done is park it, leave it, until the Supreme Court has decided whether the Court of Appeal was right and then, if appropriate, bring it back to Parliament and go through it all again."
The Prime Minister's official spokesperson told reporters on Tuesday: "We remain committed to stopping the boats and to do that we need to make it clear if you come here illegally you will be removed to a safe country.
"We have to break the cycle to deter people from making these dangerous journeys and being exploited by gangs - that is what the Bill is designed to do.
"It was voted through by the Commons and we remain committed to defending it robustly".
They said the Government's response to the 11 amendments passed by the upper chamber last night will be set out by the leader of the Commons Penny Mordaunt later this week.
Asked whether the Prime Minister had a message to peers, the spokesperson added: "Obviously it is right that Lords scrutinise legislation - we respect that approach.
"But the Government is confident that this Bill is the only effective, workable solution put forward to solving an issue that is costing lives in the Channel that is only benefiting criminal gangs and which is placing unsustainable pressure on the people of the UK and UK councils. We have to act and we have to do it quickly."
