He is understood to have crossed the Channel on a small boat in August.

The Home Secretary on Wednesday blasted “intolerable” last minute legal challenges as she scrambled to save the scheme.

A series of human rights claims meant Air France flights took off from Heathrow to Paris for three consecutive days without any small boat arrivals.

And the UK will start accepting migrants from France on Saturday.

More deportation flights are scheduled for this week and next, officials confirmed.

Shadow Home Secretary Chris Philp said: “Since Labour announced their returns deal 9909 illegal immigrants have crossed the Channel, and we are supposed to celebrate one solitary return?

“Labour must come clean. Was this removal voluntary? How many are we taking from France? And how much taxpayers’ money has already been wasted on empty flights?

“No one is fooled by tough talk from Labour. They will never do the hard work needed to tackle the lawfare that blocks removals. The truth is Labour is run by human rights lawyers – Keir Starmer and Lord Hermer – who have always sided with open borders activists over security and control.

“Only the Conservatives have a clear plan to deport all illegal arrivals, close the loopholes exploited by activist lawyers, and put in place a real deterrent through our Deportation Bill. Without that, the crossings will never stop.”

But Home Secretary Shabana Mahmood said: “This is an important first step to securing our borders. It sends a message to people crossing in small boats: if you enter the UK illegally, we will seek to remove you.

“I will continue to challenge any last-minute, vexatious attempts to frustrate a removal in the courts.

“The UK will always play its part in helping those genuinely fleeing persecution, but this must be done through safe, legal, and managed routes – not dangerous crossings.”

Another migrant is set to board a returns flight to Paris later this afternoon.

The French allegedly requested an Indian migrant because they could then offer him €2,500 to leave voluntarily.

If the migrant refuses, he will face expulsion from the country rather than the chance of asylum, as France has a reciprocal arrangement with India to accept enforced returns.

A French senior immigration official said: “We have already had an arrival this morning and will no doubt welcome two today and we expect a departure on Saturday of a group of asylum seekers to the UK.”

Migrants given deportation orders to France are lodging modern slavery claims in a bid to avoid being ordered to leave.

Sir Keir’s deal with Mr 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 – came after deportation flights failed to take off on Monday and Tuesday.

The Eritrean migrant claimed he was a victim of modern slavery.

He 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 he lodged a claim under British modern slavery laws several days later alleging he had been exploited in Libya.

The Home Office has vowed to appeal this decision.

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.”