The failure to intercept two migrant boats in two days before they reached the Kent coast was “not acceptable”, Shabana Mahmood has said.

The Home Secretary, who has ordered an urgent review by the Border Security Command, said “even one” uncontrolled landing is “one too many”.

Twenty-one people were detained after a boat arrived on the beach of Samphire Hoe, Dover, on Tuesday afternoon.

It came after a dinghy made it to shore at Folkestone on Monday morning – the first undetected landing for a year.

The thousands of migrants crossing the Channel are usually brought to shore by Border Security Command or RNLI boats.

Before Monday, no small boat arrivals to the UK coast without an escort had been officially recorded since September 6 2025.

Uncontrolled landings are so rare that last year’s incident was the only other one recorded since the Home Office began keeping data in 2023.

It will come as a blow to Border Security Command, which had suggested they were a thing of the past thanks to new surveillance technology and improved resources.

But Ms Mahmood said new smuggler crossing tactics were a sign that the Government’s efforts are “having an impact”.

She said on Wednesday: “This was not acceptable. Our improved monitoring has led to uncontrolled crossings becoming incredibly rare. But even one is one too many.

“That is why I have ordered an urgent review by the Border Security Command into how this happened, and what must be done to ensure it doesn’t happen again.

“The new tactics adopted by the smugglers, like launches from much further west in France, are a reminder of two things. Firstly, these gangs have no regard for human life. They are putting people on increasingly long and dangerous crossings.

“Secondly, our efforts are having an impact. We are making it much harder for gangs to launch vessels, forcing them to change their approach, and as a result we are significantly reducing the numbers coming here by small boat.”

A Government spokesperson said earlier: “Border Security Command officers alongside Kent police have been responding to an incident in Dover.

“Twenty-one individuals have already been detained under a swift enforcement response.

“There is a thorough investigation ongoing and it would be inappropriate to comment further.”

The Home Office has not said whether more people from the boat were being sought.

Meanwhile, a man believed to be a migrant was found dead on a beach in northern France on Wednesday, French authorities have said.

Local outlets reported the man thought to be in his twenties was found hours after a small boat departed for the UK and while other migrants hoping to make the journey remained in the nearby dunes.

Some 17,784 migrants have arrived after crossing the Channel by boat so far this year, including 5,315 since Andy Burnham became Prime Minister.

The total so far for 2026 is down 45% on the same point last year.

Shadow home secretary Chris Philp said: “Yesterday was a day of despair for the Labour Government. Our border security has descended into chaos with illegal immigrants crossing at will over ever larger distances and in ever larger boats.

“This latest fiasco shows that the French are not even trying to stop the illegal immigrants’ boats in French waters, instead they are escorting them here.

“What’s more, there have been two uncontrolled migrant landings in a week. It is a complete free for all – the Labour Government have no idea who is coming into the country.

“The only way to stop Channel crossings is to deport anyone who arrives illegally to their home country or a safe third country. That’s the only way we can end this madness.”