More than 28,300 migrants crossed the Channel from France to the UK in small boats last year.
The PA news agency reported Tuesday that, based on its analysis of British government data, at least 28,395 people reached the UK in 2021.
This is more than triple the figure for 2020, according to the figures from the UK Home Office.
The peak came in November, during which at least 6,869 people reached the UK, spurred on by favourable weather conditions.
On 11 November, a record-breaking 1,185 reached Britain in a single day.
The higher numbers were partly due to the use of bigger boats, carrying an average of about 28 people and sometimes as many as 50.
Some crossings ended tragically for many with at least 27 migrants drowning off France on 24 November during an attempted crossing in a boat which French officials likened to a children's inflatable pool.
The 27 victims were mostly men but also included seven women, a 16-year-old, and a seven-year-old child.
They were mostly Iraqi Kurds but an Iranian Kurd, Afghans, Ethiopians, a Somali, and an Egyptian were also among the dead.
The high number of migrants crossing to Britain from mainland Europe has become a political headache for British Prime Minister Boris Johnson and Home Secretary Priti Patel.
The flow of migrants has also soured Britain's relations with France, prompting an unseemly blame game even as both sides try to disrupt the people trafficking networks.
The UK government's Nationality and Borders Bill is currently before parliament. It promises tougher action against people smugglers and, controversially, migrants themselves.
If passed, the bill, opposed by rights groups, will allow the return of asylum seekers who have passed through so-called "safe third countries".