LONDON (AP) — U.K. Prime Minister Rishi Sunak faced heavy pressure from his own Conservatives to take swift action to bring down migration, as new data published Thursday showed net migration numbers were higher than previously thought.

The Office for National Statistics revised its estimates for net migration to the U.K. — meaning that the number of people arriving minus those leaving — in the year to December 2022 to 745,000. That is a new record and significantly higher than the previous estimate of 606,000 for the same period.

The more hard-line wing of the Tories called for Sunak to “act now” as a general election looms next year.

“The word ‘existential’ has been used a lot in recent days but this really is ‘do or die’ for our party,” said a statement by a group of lawmakers known as the “New Conservatives.” “Each of us made a promise to the electorate. We don’t believe that such promises can be ignored."

The Conservatives were reelected in 2019 on the back of a manifesto to “take back our borders" and break away from the constraints of the European Union.

Migration continues to be a political hot potato, although Sunak's government has focused less on legal migration than the issue of unauthorized asylum-seekers arriving on small boats across the English Channel.

The latest figures do show that net migration in the 12 months up to June 2023 was 672,000. The Office for National Statistics said that it was too early to tell if that's the start of a new downward trend.

Sunak's office at Downing Street said that net migration remained “far too high” and indicated that further measures could be introduced to bring down the figures.

Officials said they revised the 2022 figures upwards because patterns and behaviors have been shifting and less predictable than before the COVID-19 pandemic struck.

Jay Lindop, director of the international migration department at the statistics office, said the main drivers of the increase were people arriving from non-EU countries for work and study. Britain also took in hundreds of thousands of people who fled Russia's war in Ukraine and the Chinese government's crackdown on civil liberties in Hong Kong, though those numbers have slowed in recent months.

“Net migration to the U.K. has been running at record levels, driven by a rise in people coming for work, increasing numbers of students and a series of world events," he said.

“More recently, we’re not only seeing more students arrive, but we can also see they’re staying for longer. More dependants of people with work and study visas have arrived too, and immigration is now being driven by non-EU arrivals," he added.

The latest figures showed that a total of 1.18 million people are estimated to have arrived in the U.K. in the year to June 2023, while 508,000 are estimated to have left, leaving the net migration figure at 672,000.

___

Follow AP’s coverage of migration issues at https://apnews.com/hub/migration