France, Oct. 15 -- Seventeen humanitarian and activist groups filed an appeal on Tuesday in France to block a British-French migration deal that lets the UK return migrants arriving by boat in exchange for taking an equal number of visa-approved migrants from France.

The so-called "one-in, one-out" plan was signed in July and took effect in August as Prime Minister Keir Starmer's government faced growing pressure to control record levels of immigration.

The appeal was lodged with France's highest administrative court, the Council of State. The NGOs argue that the deal should have been ratified by parliament before it came into force.

"The implementation decree... is tainted with illegality, as it fails to comply with the procedure pres...