Some 28,526 people arrived in the UK after crossing the English Channel in small boats last year, according to official figures released for the first time.
The Home Office published statistics measuring irregular migration for the first time on Thursday, which confirmed the Government’s official recorded annual totals.
The data reveals the total for 2021 is slightly higher than previously anticipated.
According to the report, last year’s figure compares with 8,466 people crossing in 2020, 1,843 in 2019 and 299 in 2018.
November 2021 saw the highest number of small boat arrivals in the last four years (6,971) and the number coming to the UK in each month of last year was higher than comparable periods in 2020.
Most of the people who made the crossing last year (90%) were male, according to the Home Office data.
Three-quarters (75%) of all arrivals were men aged 18 to 39, 5% were men aged 40 and over, while 7% were women. Around 12% were children, of which 76% were boys.
Some 30% of the people arriving were Iranian nationals, 21% were Iraqi, 11% were Eritrean and 9% were Syrian.
Iranians “represented the vast majority” of small boat arrivals in 2018 (80%) and 2019 (66%). But a greater mix of nationalities have been recorded since 2020, the Home Office said.
Information on gender and nationality was not available for some arrivals.
There was an average of 28 people on board each boat in 2021 and crossings took place around two in every five days.
There were 1,034 small boats (carrying multiple people) detected arriving in the UK in 2021, compared to 641 in 2020, 164 in 2019 and 43 in 2018.
The average number of people on board small boats last year was “much higher” than in 2020, when there were 13. This is compared to 11 in 2019 and seven a year earlier.
Dr Peter William Walsh, senior researcher at the Migration Observatory at the University of Oxford, said the reasons for the rise in small boat arrivals “are not yet fully known” and it is “hard to predict how the numbers will change … over time”.
He added: “A large majority of people crossing the Channel in small boats claim asylum on being brought to the UK, and evidence from around the world suggests that changes in asylum applications are largely driven by developments well beyond UK policymakers’ control, such as crises and violence in other countries.”
The Home Office document described small boat arrivals as a “phenomenon that was rare prior to 2019 but has since increased sharply in number” and made clear this method of travel is only one of a number which could be used to reach the UK border and “seek entry without permission”.
It added: “It is not possible to know the exact size of the irregular population in the UK, nor the total number of people who enter the UK irregularly.”
Immigration minister Kevin Foster said: “This Government is fixing our country’s approach to illegal entry to the UK and asylum by making the tough decisions to end the overt exploitation of our laws and UK taxpayers.
“We know there is no simple solution to this problem but our New Plan for Immigration will deliver the fair but firm system the British people have repeatedly voted for.”
The Government’s Nationality and Borders Bill, which will make it a criminal offence to knowingly arrive in the UK illegally and introduce life sentences for those who facilitate illegal entry into the country, is currently going through Parliament.