More than 20,000 people have got into small boats and made the dangerous trip across the English Channel to the UK since the start of the year, figures show.
UK authorities rescued or intercepted 456 people who attempted the crossing on Tuesday.
Some 19,756 people had already reached the UK after navigating busy shipping lanes from France in small boats, according to data compiled by the PA news agency.
This is more than double the total for the whole of 2020.
Dan O’Mahoney, Clandestine Channel Threat Commander for the Home Office, described the journey as “dangerous, unnecessary and facilitated by violent criminal gangs profiting from misery”.
He added: “We are working with the French to stop boats leaving their beaches and crack down on the criminals driving these crossings.”
The French authorities also prevented 343 people from reaching the UK on Tuesday.
It comes a week after several migrants were feared to have been lost at sea while attempting the journey.
Among the large numbers of people seen being brought ashore in Dover on Monday was a young girl clutching the hand of a man as she was led away from the water.
During what witnesses described as a steady stream of arrivals – amid relatively calm and sunny conditions at sea – staff were spotted carrying away a brightly coloured dinghy, decorated with a tropical-style scene featuring images of parrots and flamingos.
The Channel is one of the busiest shipping lanes in the world.
Last week, Home Secretary Priti Patel described an incident in which as many as three people are thought to be unaccounted for after trying to cross from France to the UK in a dinghy as “appalling” and an “absolute tragedy”.
Two men – both Somali nationals – were rescued off the Essex coast near Harwich on October 25 and searches for any possible remaining survivors have now been called off.
The soaring number of crossings has prompted Amnesty International UK to call for an overhaul of the nation’s asylum system.
Chief executive Sacha Deshmukh said in a statement: “We need to remember that these dangerous crossings are taking place because the Government has provided no safe alternative for people to exercise their right to seek asylum here.
“If Priti Patel is truly concerned with tackling criminal gangs and their exploitation of people, she needs to set up safe asylum routes so people no longer need to depend on smugglers.
“Tragically, the Government seems more interested in playing politics with asylum than in fulfilling its responsibilities toward people in need of a place of safety.
“Asylum claims are no higher now than they were two years ago and are much lower than in other European countries, but the Government has seized on these highly visible sea crossings to justify draconian new policies criminalising people simply for seeking asylum.
“It’s misleading and deeply unhelpful to say France is a ‘safe country’ when, as ministers should know, many people who are perfectly entitled to seek asylum in Britain are trapped in miserable conditions in camps in northern France.
“We desperately need a new approach to asylum – including genuine Anglo-French efforts to devise safe asylum routes, a major overhaul of the painfully slow applications system, an end to the use of dangerous and unsuitable accommodation facilities like Napier Barracks, and a political approach based on real humanity not misinformation over so-called ‘emergencies’ in the Channel.”