More than 800 migrants in 13 boats crossed the English Channel on Saturday, according to Home Office data.
The figure is a record for a December day in recent years, and is believed to be due to a backlog of people wanting to get across to Kent because of recent bad weather.
It takes the total for the year to 41,455 people, surpassing 2024, when there were 36,816 for the entire year.
A Home Office spokesperson said: "The number of small boat crossings are shameful and the British people deserve better."
The 803 migrants were brought ashore at Dover by Border Force and RNLI vessels.
