More than 440 migrants crossed the English Channel on Monday in 15 boats, the Ministry of Defence has said.
It brings the total number of migrants making the journey from France this year to more than 13,700 people.
UK officials brought in 442 people, and French authorities stopped a further small boat which was carrying nine people after it got into difficulty.
Last year, 28,526 people are known to have crossed in small boats – up from 8,404 in 2020.
The English Channel is one of the most dangerous and busiest shipping lanes in the world.
Many migrants come from some of the poorest and most chaotic parts of the world, and many ask to claim asylum once they are picked up by the UK authorities.
The government announced in April it plans to send some asylum seekers to Rwanda to claim asylum there instead.
The first flight was cancelled minutes before take-off after legal rulings.
Campaigners against the plan say a court hearing on the policy which was scheduled for later this month has been delayed to September.
BBC News
