Net migration to the UK, the difference between the number of people entering the European country and leaving it, rose to 333,000 in 2015, the Office for National Statistics says.
According to quarterly figures from the Office for National Statistics, published Thursday, some 630,000 people came to Britain in 2015 while only 297,000 left the country.
While the total migrants entering the UK showed a slight drop of 2,000, the number of those who left the country was 22,000 less than last year.
Net migration from the European Union (EU) reached 184,000 – 10,000 more than the previous year.
The new statistics are set to further fuel the Brexit debate over the country’s future in the EU, giving a boost to the “Leave” campaigners who accuse Prime Minister David Cameron’s government of not controlling the borders.
Immigration is a defining factor in the run up to the EU referendum vote on June 23.
Anti-EU backers argue that Britain can only cut immigration by quitting the 28-nation bloc.
Boris Johnson, the former mayor of London and a fierce Leave advocate, said Thursday that the new numbers “show the scandal” of the promise by Cameron to cut the net migration below 100,000 while the UK was part of the EU.
Leaving the EU, Johnson said, was the only solution as a vote to stay in the union would mean people “kissing goodbye permanently to control of immigration.”
UK Immigration Minister James Brokenshire admitted the latest stats were “very disappointing,” and “underline the challenge this government continues to face,” but said leaving the EU is not a “silver bullet.”
A Cameron spokesman rejected claims that the London government was not in control of its borders.
“People rightly have concerns about immigration but the PM’s view is very clearly that wrecking the economy and destroying jobs by getting rid of our privileged access to the world’s biggest market is not the answer,” he added.