France plans to expand its naval fleet to intercept migrant boats in the English Channel, including those already at sea, a French government source has confirmed.

Officials have agreed to develop an interception strategy ahead of the visit of France's President Emmanuel Macron to London for a Franco-British summit on July 8, following UK criticism of French police inaction against people smugglers.

The strategy aims to stop so-called "taxi boats" before they depart for UK shores, after concerns were raised when more than 1,000 people made Channel crossings on Saturday.

The initiative falls under a UK-French agreement that aims to enhance joint efforts in combating small-boat crossings in the Channel, established earlier this year.

A French Interior Ministry source told The Telegraph newspaper: "We are aware of the high stakes involved in interventions at sea and of the need to adapt our doctrine of action.

"Today, our intervention can only take place to rescue a boat already at sea, in particular because of the criminal liability issues associated with any interception carried out for any other reason.

"We would like to change this framework so that we can operate in shallow waters, up to 300 meters from the coast, and thus intercept 'taxi boats', while respecting the principles of the United Nations Convention on the Law of the Sea, known as the Montego Bay Convention."

The source indicated Paris aims to agree "shared guidelines" in time for the July summit.

Over the weekend, French police were witnessed observing migrants, including children, boarding vessels at a beach in Gravelines, between Calais and Dunkirk, with authorities later seen escorting the boats.

UK Defense Secretary John Healey hit out at their failure to act, saying on Sunday that the UK had "lost control of its borders".

UK ministers have been urging France to implement the intervention rules agreed months ago.

Healey said: "They're not doing it, but for the first time for years, we've got the level of cooperation needed… We've got the agreement that they will change the way they work, and our concentration now is to push them to get that into operation, so they can intercept these smugglers and stop these people in the boats, not just on the shore."

The UK's Home Secretary Yvette Cooper urged France to begin intercepting small boats "as swiftly as possible" after 1,195 people reached the UK in just 19 boats on Saturday.

Channel crossings have already reached 14,812 this year, marking a 42-percent increase from the same period last year and nearly double the figure from 2023.