The UK will press French authorities to crack down on migrants attempting to cross the Channel in small boats, ministers have pledged.
A record number of unaccompanied children arrived in the UK on Friday.
Schools Minister Nick Gibb said the government was also considering how to use “maritime assets” in order to prevent crossings.
And, writing in the Daily Telegraph, Immigration Minister Chris Philp said migrants should be fingerprinted.
However, it is unclear what the proposal will amount to, as the fingerprints of asylum seekers are already stored under the European Union Eurodac system.
Mr Philp said migrants would know “they face real consequences if they try to cross again”, and added he would “negotiate hard” with French officials about how to deal with the crossings.
In a rare sighting, BBC Europe reporter Gavin Lee witnessed a rubber boat with up to 20 people on board, including a baby, depart from a tourist beach in the north of France on Saturday morning.
The “overloaded” boat struggled for almost an hour at the water’s edge, he said, adding there was no sign of any surveillance on the beach in the harbour of Gravelines since the early morning.
Across the Channel in Dover, BBC reporter Simon Jones said the coastguard was dealing with a number of incidents.
Our reporter said local people have been asking why more is not being done by the French to patrol the coastline, but authorities across the Channel have said they need more finances from the UK government.
Questions have also been raised about why once people arrive in the UK they are not sent back to France.
Home Secretary Priti Patel has described the situation as “complex”, saying in a tweet on Friday that the government faces “serious legislative, legal and operational barriers”.
The Home Office said it is possible that the Royal Navy could be brought in to patrol the Channel’s migrant traffic.
But the idea of using the Navy was branded “completely potty” by a Ministry of Defence source, the PA news agency reports.
The source said such action would be “inappropriate and unnecessary” and that military resources should not be used to address “political failings”.
Former Labour home secretary Jack Straw said any attempt to model Australia’s controversial “push back” tactics – used against migrants travelling from Indonesia – would not work and could lead to boats capsizing.
“The crucial point here is the obvious one, is that it requires the co-operation of the French,” Mr Straw said.
Asked about the potential for Navy involvement, Mr Gibb told BBC Breakfast that the government would look at how it could “use maritime assets”.
Mr Gibb added: “We are determined to tackle it, from a humanitarian point of view as much as from an immigration point of view.”
Former director general of UK Border Force, Tony Smith, said smugglers have identified a “loophole” in international law.
The UN’s 1951 Refugee Convention says that once a person is in the jurisdiction of a country – such as territorial waters – then authorities are obliged to rescue people, bring them ashore, and allow them to lodge an asylum application, Mr Smith told BBC Radio 4’s Today programme.
However, under a long-standing EU deal, called “Dublin III”, the UK has the right to send back anyone who is seeking asylum if they could have reasonably claimed it in another country along the way.
That arrangement will cease at the end of the Brexit transition period – next January – unless the UK and the EU agree a similar deal.
Migrants spotted setting off from France
Our team arrived just before first light to the main tourist beach of Petit Fort Philippe near Gravelines this morning, 20 miles east of Calais.
Within minutes, we spotted more than 20 migrants carrying a rubber boat and its motor in the distance.
They were holding it above their heads as they walked for 15 minutes from the dunes, past the beach huts to the sea.
Children were at the back, holding hands and wearing life jackets. When they first got into the water, they were clearly in trouble.
The boat was overloaded with 21 people on board, letting in water and came back to shore.
Several men, who appeared to be smugglers, appeared from the dunes to the shore and took a woman and her child off the boat. They then relaunched.
It looked dangerously close to sinking and still overcrowded despite the calm waters.
In total, it took almost an hour before the boat left. In this time, there was no sign of any surveillance. We called the police to alert them, worried that the boat may be in imminent danger.
They told us they were on the way. Four hours later, there is still no sign of them.
Several bird spotters on the beach had witnessed the same thing. One told us that this is the third time this week that boats have left from here, and that each time, he could hear children crying before they got into the boat.
More than 1,000 migrants arrived on UK shores using small boats in July, while 235 were detained this Thursday – the record for a single day.
MPs have launched an inquiry into the rising numbers entering the UK, while Labour has accused ministers of “failing to get to grips with the crisis”.
Fisherman Matt Coker told the BBC it was “very common” for him to see people trying to cross the Channel in inflatable boats, adding that he saw them “every calm day”.
“Some of the things I’ve seen it defies belief,” Mr Coker said, adding that he had witnessed people paddling across the Channel in inflatable canoes and kayaks with shovels and bits of wood.
Meanwhile, French police have told the BBC that they are catching more migrants attempting to cross to the UK by sea than ever before.
Officers said they have intercepted 10 times the number of migrants from boats in French waters in July this year, compared to the same period last year.
They said their success rate in catching migrants has increased from 40% in 2019 to 47% in 2020.