A former Royal Marine and veteran of combat in Iraq and Kosovo, Dan O’Mahoney will now be tasked with stemming the flow of migrants into Britain from France via the English Channel. O’Mahoney was appointed ‘Clandestine Channel Threat Commander’ by Home Secretary Priti Patel on Sunday, and is the first official to assume the new role.

“The number of illegal small boat crossings is appalling,” Patel said. “We are working to make this route unviable and arresting the criminals facilitating these crossings and making sure they are brought to justice.”

A mere 20 miles (32km) separates Britain and France at the narrowest point of the English Channel. A recent spell of warm weather – coupled with a slowdown in truck traffic through the Channel Tunnel – has seen hordes of migrants traverse the waterway in dinghies, pleasure craft, and kayaks.

On Thursday, 235 people landed on British shores in 17 different vessels, a record number in one day. The previous record was set a month earlier, when 202 people were caught by Border Force officers. More than 4,200 have arrived this year so far, with only 155 returned between January and April.

Immigration Minister Chris Philp has repeatedly denounced French authorities for failing to intercept the boats on their way out. Anti-immigration campaigners, meanwhile, have slammed the government for housing the migrants in hotels, with Brexit Party leader Nigel Farage calling the accommodation policy a “soft touch,” and the boat landings a “shocking invasion.”

O’Mahoney will be responsible for arresting and prosecuting the human traffickers who organize many of the crossings, and for organizing interceptions and the return of boats to France.

Philp is set to meet his French counterparts next week, and will reportedly press the French to catch and fingerprint anyone attempting to cross the channel, so that they can be deported to their country of origin or detained for breaking the law.

“These crossings are not only dangerous and illegal, but totally unnecessary,” he wrote in a column on Saturday. “Migrants who set off from the shores of France have travelled through safe EU states with well-run asylum systems. The British people have been very clear they want to take back control of our borders and we must deliver.”