The migrants successfully argued they were victims of human trafficking

Labour's one in, one out deal with France has been dealt a huge blow as five migrants have won a High Court battle.

The migrants have claimed their deportations were unlawful, alleging they are victims of trafficking.

The High Court support the appeal, where their lawyer argued their fundamental rights could not be "sacrificed for the sake of expediency and speed of decision-making or a desire to accelerate removals."

The Anglo-French agreement means people who arrive via small boat can be apprehended and sent back to France in exchange for an equal number of people who apply through legitimate routes.

Shabana Mahmood changed the policy to disallow migrants from appealing rulings that deem them not victims of trafficking, clearing the route for deportation.

The High Court found Channel migrants were often too malnourished, lacked English-speaking skills and sleep-deprived to present evidence to support their trafficking case.

Crucial evidence such as medical examinations and legal reports often might not emerge for weeks, despite trafficking claims normally decided on within five days.

This meant, the court rules, there was a higher chance many cases of genuine human trafficking would be missed.

As a result, Mr Justice Sheldon, rules Shabana Mahmood's amendment to the guidance had a "negative impact" and was unlawful on some of the migrants.

He said: "In my judgment, such a decision-making process cannot be regarded as robust and effective, and so could not have been within the contemplation of Parliament."

In the UK, victims of human trafficking undergo an assessment process in which an initial finding of "reasonable grounds" to believe someone is a victim prevents them from being removed from the country for at least 30 days.

In his 115-page judgment, Mr Justice Sheldon noted these "reasonable grounds" decisions are often made within five working days.

First interviews of people who have arrived by small boat sometimes taking place within hours of arrival, including in the middle of the night.

The judge said "there are bound to be many cases where a victim of trafficking will not be identified" due to decision makers do not have the needed evidence.

He added 79 per cent of initial decisions that were reconsidered in 2025 received a different outcome.

The judge continued: "There will often be language difficulties, which will not be resolved by the use of an interpreter.

"The questions posed about exploitation may not be fully understood.

"In these circumstances, it would not be surprising if incomplete accounts are given of alleged trafficking experiences or if none are given at all."

However, he did rule the majority of Home Office decisions, such as asserting their asylum claims were unfounded and protection claims as inadmissible, were lawfully made.

Since the treaty came into effect, 921 small boat migrants have been returned under the scheme - this equates to 3.5 per cent of all small boat arrivals.

The UK has accepted 896 migrants from France in the same timeframe.

A Home Office spokesman said: “Last-minute modern slavery claims must not be used to frustrate the removal of illegal migrants.

“We are reforming our laws to stop dubious last-minute claims, while strengthening protections for those who need them.

“The Home Secretary will fight this in the courts and appeal this judgement."