Labour’s migrant deal with France is “descending into farce” after left-wing activists vowed to try and block a new deportation centre. Shabana Mahmood pledged to help Paris pay for the facility near Dunkirk so that deportations can be ramped up.

But a French environmental group has claimed it does not comply with local planning rules. Flemish-Artois Coastal Environmental Defense Assembly has alleged the facility is located in an industrial zone where residential accommodation is not allowed under planning rules.

And the group’s president, Nicolas Fournier, told the BBC the group was “still trying to hinder this process of building the detention centre with the appeal”.

He said: “Putting so many resources solely into repression, with ever more police, doesn’t work.

“So we really need to find other solutions, because we can’t continue to allow this risk of seeing people take to the sea in unacceptable, deplorable conditions that endanger them.”

Shadow Home Secretary Chris Philp told GB News: “The Government’s so-called deal is descending into farce. They have already handed over half a billion pounds unconditionally.

“Yet in the last few days alone over 1,000 illegal immigrants have crossed the Channel with the French barely lifting a finger. Now it looks like their detention centre won’t ever open.

“No wonder more illegal immigrants have crossed under Keir Starmer than any other Prime Minister – up 45 per cent up since the election. The only way to stop this is to leave the ECHR and deport all illegal immigrants within a week of arrival. But Labour is too weak to do this.”

Reform’s Home Affairs spokesman Zia Yusuf said: “Shabana Mahmood is now set to waste even more taxpayer money funding expensive lawyers just to try and get a single detention centre open in France.

“This is yet another example of Labour claiming they want to stop the boats while refusing to do what it actually takes – leaving the failing ECHR and detaining and deporting every illegal migrant, as Reform would do.”

Home Secretary Ms Mahmood has confirmed Paris will use a new detention centre in Dunkirk to remove hundreds of asylum seekers every year.

But Britain will pay France to do this, the Daily Express understands, as part of Labour’s £660million deal with Emmanuel Macron’s Government. Migrants will be deported back to their home countries or other EU countries they have passed through, the Home Office said.

The deal will see officers targeting and detaining small boat migrants on French beaches. They will then be taken to the removal centre to be deported.

While the site is under construction, officials will use a removal centre in Coquelles.

Home Office sources said that if it doesn’t lead to a reduction in crossings, the payments will be cancelled.

Ms Mahmood has agreed to give Paris £500 million for an increase in police patrols, a new vessel to intercept migrant taxi boats, two helicopters, drones and a camera surveillance system.

And the Home Office will give the French another £160m to test new tactics to stop Channel migrant crossings. One of the proposals being tested is paying France to deport migrants on their coastline.

Critics blasted the latest handouts as the three-year package will take the total given to Emmanuel Macron’s Government to more than £1.3 billion.

Paris will receive £220 million this year as part of a desperate bid to prevent a Summer surge in arrivals.

A Home Office spokesman said: “France has committed to building this detention centre. The UK will only pay when the work is completed.

“France is a critical partner in tackling illegal migration. We continue to work closely together to stop migrants entering the UK on small boats. We will do whatever it takes to secure our borders.”