Nearly 30,000 migrants crossed the Channel to Britain from mainland Europe in small boats in 2023, an annual drop of more than a third, government figures released Monday showed.
However, the unauthorised arrivals of 29,437 people on the southeast English coast remains the second largest yearly tally since officials began publishing the numbers in 2018.
The perilous journeys across one of the world's busiest shipping lanes have become a huge political problem for the Conservative government, with Prime Minister Rishi Sunak pledging last year to "stop the boats".
One of five key promises he made for 2023, the persistently high number of arrivals could haunt the Tory leader as he bids to win a general election due this year.
Sunak said last month there was no "firm date" for meeting his pledge.
The beleaguered leader will likely point to a 36 percent reduction in small-boat arrivals last year, after a record 45,000 migrants made the journey in 2022.
His ministers have claimed Britain's £480 million ($610 million) agreement with France to increase efforts to stop the migrants is starting to pay off, alongside fast-track return deals struck with countries such as Albania.
But the main Labour opposition -- which has enjoyed double-digit poll leads for the duration of Sunak's nearly 15 months in power -- says he has failed to keep his promise and his immigration policy is in chaos.
The ruling Conservatives had hoped to deter the crossings by preventing all migrants arriving without prior authorisation from applying for asylum and sending some to Rwanda.
But the policy remains stalled after the UK Supreme Court ruled that deporting them to the east African country is illegal under international law.
The cross-Channel journeys on small inflatable vessels, which are often overloaded and unseaworthy, has repeatedly proved deadly.
In one of the latest tragedies, at least six men died and dozens more required rescuing in August after a small vessel bound for the southeast English coast from France sank.
In November 2021, at least 27 people drowned when their dinghy capsized. (AFP)
