(Bloomberg) -- Net migration to the UK fell last year but remained at historically high levels, underlining the challenge facing Prime Minister Rishi Sunak as tries to show he is cracking down on overseas arrivals ahead of the July 4 general election.

An estimated 685,000 more people moved to the UK than left the country, according to the Office for National Statistics. That’s down from a record 764,000 in 2022, a figure that was revised up by 19,000.

Polls show immigration is one of the top issues looming over the election, and Sunak has made reducing the figures a core promise to voters. Net migration is still far higher than levels before the pandemic. The Tories had promised to get migration down to the “tens of thousands” but abandoned the pledge in 2019 when it became clear it was not deliverable.

Under Sunak, the debate has widened from stopping boats carrying asylum seekers to limiting legal migration even as businesses warned of worsening labor shortages. Sunak faces pressure from the right wing of his party, as well as from Reform UK, which backs a net zero migration stance luring Brexit supporters.

The Labour Party, leading the ruling Conservatives by 20 points in opinion polls, is likely the one that will have to deal with the issue in six weeks time. Leader Keir Starmer has promised to implement a new post of border security commander to tackle Channel crossings.

“Net migration remained exceptionally high in 2023 but is set to fall, possibly quite sharply, in the year ahead,” said Marley Morris, IPPR associate director for migration, trade and communities. “The reality is there are some tough choices on immigration which will need to be grappled with, whoever wins the upcoming election. Crude cuts could exacerbate staff shortages in health and care and imperil university finances.”

The debate over migration has pitted politicians against businesses and universities that rely on foreign workers and students. Many of the visas being granted are also for workers in public services such as health and social care, where staff shortages are acute.

The government has promised to tackle the issue by getting more British workers into work currently done by migrants. 

A promise to cut net migration to the “tens of thousands” was made by then-prime minister, David Cameron, in 2010 and maintained by the Tories for almost a decade — despite the fact the the figures remained well above that level throughout. Only in 2019, when Boris Johnson became Tory leader, did the party ditch the pledge. His successors, Liz Truss and now Sunak, have spoken of immigration being far too high but have shied away from putting a figure on what they think it should be. 

Since Brexit, most migrants arriving in the UK have come through humanitarian routes, such as those put in place for Ukranians, work visas, mainly for those with health and care jobs, and as students.

Net migration in the year to December was driven by the arrival of over a million non-European Union nationals, far outnumbering the 233,000 who left the country. In contrast, British and EU nationals brought down net migration down as more than 100,000 left on balance. 

Economists have warned that clamping down on migration risks depriving the UK of potential growth unless productivity dramatically improves. The recent increase in migration has boosted economic output and driven up tax revenues, helping Chancellor Jeremy Hunt deliver tax cuts. 

“The government may well have succeeded in putting immigration firmly on a downward path,” Jonathan Portes, a professor of economics at King’s College London, wrote in a blog post. “The price, however, is likely to be high, and paid both by taxpayers and those who use public services – that is, all of us.”

Getting immigration down will be a challenge. The office for National Statistics projects the number of people in the UK will grow by 6.6 million by 2036 – almost all from immigration. The growing population piles pressure on the government to ensure public services can meet the extra demand and there is sufficient housing.

Many Brexit voters hoped leaving the European Union would reduce net migration as freedom-of-movement rules ended. Instead the number of people arriving in the UK has accelerated due to labor shortages. Non-EU immigration for work-related reasons climbed by almost 150,000 to 423,000 in 2023, replacing study as the main reason for long-term migration. Almost half of those people came from India or Nigeria, most commonly in the health and care sector.

For the first time, those arriving as dependants from non-EU countries outnumbered main applicants on work visas. There were 14,000 more dependants than main applicants, at 219,000.

Sunak has made plans to bring down that number by banning most students and care workers from bringing relatives to the UK. He’s also raised the salary threshold required for skilled foreign workers to get a visa to £38,700 ($49,248) a year, although care workers are exempt from that.

Read more: New UK Migration Rules Risk Exploiting Care Workers, Panel Says

The new rules are already having an impact on UK businesses and universities. Earlier this month, CEOs including from Anglo American and Siemens wrote a letter to Sunak saying they were “deeply concerned” about shrinking international student numbers driven by government policy, and the impact this will have on the UK’s “skills base, future workforce, and international influence.”

Student main applications were down 15%, while dependant visa applications declined 80% in the first quarter of 2024 compared to the same period last year, according to Home Office data. Deposits paid by international students as part of their visa application for the September 2024 intake were down 57%, compared to the previous intake, separate figures from Enroly showed.

ONS migration numbers also indicated that non-EU nationals who came to the UK on study visas were increasingly leaving the country after they arrived in large numbers in the immediate aftermath of the pandemic.

The government is mulling whether to scrap the graduate visa programme, which enables overseas student to live and work in the UK for a maximum of two years after graduation, as it faces pressure from many Tories to act.

The Migration Advisory Committee warned the government against ditching the graduate visa route, saying it found “no evidence” the scheme was abused as a backdoor entry.

©2024 Bloomberg L.P.