LONDON — The first undocumented migrant has been sent from the U.K. to France as part of an asylum deal struck between the two countries.

The man, who crossed the English Channel in a small boat in August, was deported on a commercial plane. Under the “one in, one out” scheme, agreed between London and Paris in July, he can be exchanged for an asylum-seeker who has never crossed the Channel and has a British connection.

The Home Office said further flights are due to take place this week and next, with the first arrivals in the U.K. through the new legal route expected “in the coming days.”

The Home Office had hoped the first deportation would happen earlier this week, but it was delayed after a High Court judge on Tuesday imposed a “short period of interim relief” on another migrant’s departure so lawyers could determine whether the person had been a victim of modern slavery.

Home Secretary Shabana Mahmood said it was “an important first step to securing our borders” and “sends a message to people crossing in small boats: if you enter the U.K. illegally, we will seek to remove you.”

Mahmood said she would “continue to challenge any last-minute, vexatious attempts to frustrate a removal in the courts.”

More than 50,000 people have crossed the Channel in small boats since Labour came to power in July 2024. Prime Minister Keir Starmer entered office pledging to “smash the gangs” after his predecessor Rishi Sunak’s election defeat was partially blamed on failing to “stop the boats.”

Paris also plans to reduce the number of boat crossings by changing rules on how it intercepts boats at sea.