In the first legal challenge against the deal, in the High Court in London, his lawyers argued he needed more time to present evidence that he might have been the victim of modern day slavery – and the decision to remove him had been rushed.

Eritrean man who arrived in the UK by small boat has won a last-minute legal claim to temporarily block his removal to France.

The 25-year-old was due to be returned on Wednesday under the “one in, one out” returns pilot scheme agreed in July between the UK and France.

In the first legal challenge against the deal, in the High Court in London, his lawyers argued he needed more time to present evidence that he might have been the victim of modern day slavery – and the decision to remove him had been rushed.

The injunction raises serious questions about whether other migrants allocated to flights will use the same grounds to delay or block their removal.

Lawyers for the Home Office had argued that he could have claimed asylum in France. They added that delaying his departure could encourage others allocated to the return flights this week to make similar claims, and undermine the public interest in deterring lethal small boat crossings.

But during the hearing, it emerged that while the home secretary’s own officials had rejected his claim that he was a victim of slavery, they had also said in a letter today that he had a right to make further representations – and they would not expect him to do that from France.

Mr Justice Sheldon, who rejected the man’s claim that he would be left homeless and destitute in France, said that he would nevertheless have to temporarily block the man’s departure in light of that development.

“There is a serious issue to be tried in relation to the trafficking claim and whether or not the Secretary of State has carried out her investigatory duties in a lawful manner,” he said.

“If there was a reasonable suspicion that he was trafficked – and that does not mean trafficked in or from France – that would amount to a statutory bar to removal for at least a short period of time.”

The judge said the man’s lawyers must do all that is possible to make further representations within 14 days, so that his case can be finalised at a future hearing.

A spokesperson for the Home Office told the BBC that the government expected the first returns to take place imminently and that the interim ruling would not prevent delivery of the wider policy. By BBC