LONDON -- Net migration to the United Kingdom rose to a record high of around 504,000 in the year to June 2022, official statistics showed on Thursday, driven by an increase in the number of non-European Union nationals.

The Office for National Statistics (ONS) said a recovery of travel following COVID-19, and an increase in arrivals of international students who had been studying remotely during the pandemic had contributed to the rise.

An estimated 1.1 million long-term immigrants arrived over the period, up 435,000 on the previous year. The biggest proportion of those leaving Britain were EU nationals.

Three new visa schemes - for Ukrainians, Afghans and Hong Kong British nationals - together added around 138,000 to the number of arrivals.

"A series of world events have impacted international migration patterns in the 12 months to June 2022. Taken together these were unprecedented," Jay Lindop, Director of the ONS Centre for International Migration, said.

"Migration from non-EU countries, specifically students, is driving this rise," Lindop added. "The many factors independent of each other contributing to migration at this time mean it is too early to say whether this picture will be sustained."

Concerns over the impact of immigration were one of the big drivers behind Britain's 2016 vote to leave the EU. At the time then Prime Minister David Cameron had failed for several years to hit a net migration target of less than 100,000 a year.

The ONS said both the immigration and net migration figures, which do not include those arriving via clandestine routes such as on small boats across the Channel, were the highest since it began collecting migration statistics in 1964. The previous record high for net migration was just over 330,000 in 2015.

A spokesman for Rishi Sunak said the prime minister was "fully committed" to bringing overall numbers down.

"We're considering all options to make sure the immigration system is delivering," he said.

The opposition Labour Party said the figures showed the government had mismanaged the immigration and asylum systems and "completely failed to get a grip."

TACKLING ILLEGAL IMMIGRATION

Migration levels have been in the headlines again in Britain in recent weeks as some business leaders called on the government to liberalize immigration to help boost growth. That was rejected by Sunak who instead emphasized the need to tackle illegal immigration to build trust in the migration system.

Sunak and interior minister Suella Braverman have also come under pressure to do more to stop illegal migrants making perilous journeys across the Channel, with criticism of conditions at an overcrowded processing center in southern England and a fire bomb attack on a similar site nearby.

Earlier this month, Britain signed an agreement with France to ramp up efforts to stop migrants.

Figures released by the government on Thursday showed 33,029 people were detected arriving by small boats across the Channel between January and September this year, with 61% of those arriving over the summer in the months July to September.

August saw the highest number of small boat arrivals of any month since data has been collected, it said.

A further 6,371 arrived by other irregular means in the first nine months of the year, the government said.

Reporting by Sachin Ravikumar and Farouq Suleiman, Editing by Kylie MacLellan, Kate Holton, Kirsten Donovan