Nearly 600 people were stopped by border patrols while trying to cross the English Channel in more than a dozen separate incidents in one day.
After British authorities detained 378 people on their side of the Channel, UK Home Secretary Priti Patel declared her “unwavering determination” to put a stop to illegal migration.
The 12 separate swoops on SUnday were the latest in a mounting crackdown on cross-Channel migration as record numbers of people try to reach the UK on small boats.
Another 178 people were intercepted by French authorities in five further incidents and stopped from reaching British shores.
France last week agreed to widen its patrols of its northern coast but is calling for help from the EU’s border agency, Frontex.
Frontex’s operations – which have come under scrutiny because of alleged human rights breaches in the Mediterranean – are mainly focused on people trying to cross the EU’s southern borders in Greece, Spain and Italy.
But French Interior Minister Gerald Darmanin said it should help to curb cross-Channel migration after the number of crossings rose to record levels.
He said France would push for greater EU action on asylum seekers when it takes on the rotating presidency of the bloc in January.
“I myself have contacted Frontex, which is predominantly taking care of Southern Europe, and asked them to deal with Northern Europe, too,” he said.
“Sixty per cent of migrants who come here, come via Belgium. So, our spectrum must be very wide. We need European air surveillance.”
More than 8,400 people have crossed to the UK so far this year, exceeding the figure for the whole of 2020.
At least 430 migrants crossed the Channel last Monday, in a record for a single day. The previous daily high of 416 was set in September last year.
Boat crossings have increased since the start of the pandemic while fewer people stowed away in lorries after restrictions were brought in.
Authorities on England’s southern coast recently said they could not take in any more unaccompanied children because of the pressure on the system.
France and Britain last week unveiled a new agreement to tackle illegal migration with patrols taking place along a wider stretch of the French coast.
The UK government believes that smuggling gangs have moved further up the coast and sent migrants on longer, riskier journeys as border police step up patrols.
Britain pledged to pay €62.7 million ($73.9m) over the next year to support France’s efforts.
Visiting Calais, a key Channel port on the French coast, Mr Darmanin said the money would allow France to double its manpower at its northern border.
“It’s a very good thing for Calais and for France,” he said of the deal.
The UK’s House of Commons last week voted to advance a bill which would bring in new criminal offences for people who enter the UK illegally.
The bill was criticised by groups such as Refugee Action which described it as “pure political theatre that makes no attempt to improve our asylum system”.
Ms Patel said on Sunday that the bill would “make people think again before attempting to enter this country illegally”.
“The British public should be in no doubt of our unwavering determination to stop these dangerous crossings from safe EU countries and take down the evil criminal gangs behind them,” she said.
“We are utilising all aspects of government to tackle this issue and our significant actions are having an impact.”