Allowing migrants to claim asylum from France “will only attract vast numbers” of people to the Channel's coastline, a former Border Force chief has warned.

French interior minister Gerald Darmanin called for a UK-EU migration treaty to curb crossings in the wake of 12 deaths off the coast of Cap Gris-Nez on Tuesday.

But Tony Smith, former Director General of Border Force, warned “any asylum processing centre” in France will lead to people traveling to northern France “in hope and expectation they will be approved to come to the UK”.

Mr Smith also declared migrants who cross the Channel should be “returned instantly” or deported to either home country or a safe third country.

Writing in the Daily Express, he warned: “The government has committed to “smash the gangs” behind this evil trade.

“But we have already deployed significant assets from the Border Force, Immigration Enforcement and the National Crime Agency in that endeavour.

“And whilst there have been some successes, there have always been other gangs waiting in the wings to take over. Sadly, there is so much money involved that the smugglers won’t just give up.

“What we need is a real deterrent to break their business model.

“Some argue that the answer is to open up safe and legal routes from France in order to deter crossings.

“Short of opening the border completely to allcomers (which may be their ambition), that won’t work either.

“Any “asylum processing” centre in France will only attract vast numbers of irregular migrants and asylum seekers from across the Schengen zone to the region, in hope and expectation they will be approved to come to the UK.”

A pregnant woman and six children were among those who lost their lives in what is being described as the deadliest Channel crossing tragedy since 2021, when their boat was "ripped apart" and sank off the northern French coast of Cap Gris-Nez on Tuesday.

Sources in France have claimed the asylum seekers on the boat turned down the chance to be rescued minutes before the disaster.

Investigators have revealed that the Abeille Normandie – the Normandy Bee rescue vessel – took 15 people off the stricken boat soon after Mayday calls were put out by some on board.

A source said: “Fifteen people got on to the Abeille Normandie, saying they wanted to be rescued as soon as possible.

“The remaining 65 continued on their voyage, and capsized soon afterwards.”

It has also emerged that the dinghy had been modified to try to make it go faster.

Rigid supports were taken out of the bottom of the overcrowded boat, and this made it particularly unstable. sources said.

Axel Baheu, the skipper of the French trawler Murex, described the horrific scene in the Channel as people tried to rescue those in the water.

Describing the first person pulled out of the sea, Mr Baheu told Le Monde: “He was already cold, his eyes were open and foam was coming out of his mouth, he had no pulse.”

Mr Baheu heard a phone ringing, saying: ‘It was probably someone calling to see if he was okay or not.’

Dozens of migrants continued to make the journey on Wednesday, with more people pictured being brought ashore in Dover, Kent, amid calm weather conditions at sea.

Home Office figures show 317 migrants made the journey in five boats on Tuesday, suggesting an average of around 63 people per boat.

This takes the provisional total number of migrants who have arrived in the UK so far this year after crossing the Channel to 21,720 - 3% higher than this time last year.

Downing Street rejected calls for a new UK-EU pact.

A spokesman said: "We have no plans to be part of an EU scheme on asylum, but we will continue to work with European partners to shut down smuggling routes and smash those criminal gangs."

Angele Vettorello, from Utopia 56 - which supports displaced and homeless migrants in France, warned the crossings are “not going to stop.”

She added: "Even this morning we saw more than 200 people trying to cross and have been stopped (by police).

"We see it every month... every death at the border, the people don't stop crossing."

She said a lot of police were at the shoreline, with officers intervening overnight and in the morning.

Last week was "really busy" for crossings and there had been a "huge increase" in the number of people dying in the Channel this summer, Ms Vettorello said, adding: "We know a lot of people who were stopped to cross and were back to shore during those seven days.

"We received calls from people in distress in boats in the Channel, we received for example eight calls from eight different boats on Friday."