Sir Keir Starmer has been branded “clueless, arrogant and useless” as his migrant returns deal with France descended even further into farce.
A series of human rights claims meant Air France flights took off from Heathrow to Paris for a third consecutive day without any small boat arrivals onboard.
And the UK could start accepting migrants from France on Saturday.
The Prime Minister’s deal with Emmanuel Macron was thrown into disarray on Tuesday night when the High Court blocked the deportation of an Eritrean migrant.
The human rights claim – the first challenge to reach court over the deal – comes after deportation flights failed to take off on Monday and Tuesday.
The Eritrean migrant claimed he was a victim of modern slavery.
The man arrived in Britain by small boat on August 12 after his mother paid £1,000 to smugglers.
The following day during an asylum screening interview with the Home Office, he was asked if he had been exploited and replied ‘no’, court papers showed.
But a few days later he lodged a claim under British modern slavery laws alleging he had been exploited in Libya.
The Home Office has vowed to appeal this decision, as Home Secretary Shabana Mahmood slammed lawyers for “last minute attempts to frustrate” removals.
Insiders insist they still plan to deport migrants this week.
Home Secretary Shabana Mahmood said: “Last minute attempts to frustrate a removal are intolerable, and I will fight them at every step.
“Migrants suddenly deciding that they are a modern slave on the eve of their removal, having never made such a claim before, make a mockery of our laws and this country’s generosity.
“I will fight to end vexatious, last-minute claims. I will robustly defend the British public’s priorities in any court. And I will do whatever it takes to secure our border.”
Ms Mahmood has ordered a review into modern slavery laws amid fears they are being exploited by migrants.
But Shadow Home Secretary Chris Philp told the Daily Express: “Labour’s gimmick deal has already collapsed into chaos and farce.
“I have been warning the government for months that human rights and modern slavery claims would sink their plans.
“They planned to allow 95% of illegal immigrants to stay and remove just 5%, but they can’t even do that.
“And now it appears they may be about to ship in 50 immigrants from France this weekend without having sent a single one the other way.
“It would be 50 on and zero out.
“This Labour government has plumbed new depths of incompetence and dishonesty.
“We need to end the Human Rights Act for immigration matters and deport every illegal immigrant immediately upon arrival.”
Former Home Secretary Sir James Cleverly said: “Starmer’s 1-in-1-out” asylum scheme with France looks set to become a “50-in-0-out” scheme by Saturday.
“He cancelled the Rwanda scheme with no replacement and is now reaping the whirlwind.
“Starmer is clueless, arrogant and useless”.
Shadow Home Office minister Katie Lam said: “It’s no surprise the Government’s French ‘deal’ is failing. “
“To stop small boat crossings, swiftly detain and remove all who come here illegally.
“Anything less just will not work. In choosing not to do this, the Government is choosing not to fix this terrible problem.”
Immigration officials are understood to have needed more time to assess human rights claims lodged by migrants facing deportation on Wednesday.
Research compiled by Migration Watch revealed 181,329 asylum seekers have crossed the Channel since 2018.
This is compared to the 180,779 in the Army, Royal Navy, Royal Marines and Royal Air Force.
Labour has faced a torrent of criticism for axing the Rwanda deportation scheme and removing the UK’s only deterrent.
It has pinned its hopes on “smashing the gangs”, bolstering ties with EU countries to go after the smugglers, a slew of return deals and more “upstream work”.
Left-wing charities have also been scrambling to provide migrants with lawyers to avoid being returned to France.
Care4Calais told supporters: “We can reveal that our Legal Access department’s work is also paying off. Our caseworkers have been busy signing detainees up with legal firms to secure legal representation and challenge their detention. And already some clients’ deportations have been postponed.
“As well as sending your emails and tweets to Air France, will you chip in to help fund more casework hours and help secure crucial legal representation for those being held in detention?”
Liz Kendall, the Technology Secretary, told Times Radio she would not comment on “operational details”, but said: “This is one person, it is not going to undermine the fundamental basis of this deal.
“This decision is disappointing, but it won’t prevent the rest of that deal going ahead.”
Mr Justice Sheldon said on Tuesday evening: “It seems to me there is a serious issue to be tried with respect to the trafficking claim and whether or not the Secretary of State has carried out her investigatory duties in a lawful manner.”
He said based on the arguments made in court, it did not seem to him that there was a “real risk” the man would “suffer destitution if he was to be returned to France”.
The judge added that the case “should come back to this court as soon as is reasonably practical in light of the further representations that the claimant… will make on his trafficking decision”.