More than 600 migrants crossed the English Channel on Sunday, the highest number on a single day so far this year, the Home Office said.
Some 616 people were detected making the journey from France in twelve small boats.
The previous daily high for this year was 497 people on April 22.
The total number of migrants making the journey this year is more than 8,000, which is about 2,000 less than at the same point last year.
Speaking in Dover last week, Prime Minister Rishi Sunak said his plan to cut the number of migrants crossing the Channel in boats was working and numbers were down for the first time.
Mr Sunak told BBC political editor Chris Mason that crossings to the UK were down by a fifth, and figures for Albanians heading to Britain were down by 90%.
At this point last year, the cumulative figure had just passed 10,000. The total number of crossings last year was 45,755.