LONDON - The number of European Union nationals working in Britain fell for the first time in eight years at the start of 2018, according to official figures on Tuesday that are likely to stir unease among some employers.

Less than a year before Britain is due to leave the EU, the Office for National Statistics said 2.292 million nationals of other EU countries were working in Britain in the first three months of 2018, 1.2 percent fewer than a year before.

The fall was driven mostly by workers from the eight eastern European countries which joined the EU in 2004, whose numbers have fallen by 9.1 percent over the past year.

But the number of Romanians and Bulgarians - who have only been able to work freely in Britain since 2014 - continued to rise sharply, increasing by 19.8 percent over the year.

Looking at EU-born workers rather than EU nationals - a measure preferred by some academics as it includes long-term immigrants who acquire British citizenship - the number of workers rose by 0.3 percent, the smallest increase since 2010.

A desire to control migration into Britain was one of the main drivers of the vote to leave the EU in the 2016 referendum, although business groups have said clamping down on migration will probably hurt the economy.

In March, a report commissioned by the British government warned that restricting migration into Britain will likely lead to weaker economic growth.

Tuesday’s figures chimed with separate migration data that have shown a sharp decrease in the number of people moving to Britain from the EU.

“If this trend continues, it will sound alarm bells for employers especially in low-skilled sectors,” Gerwyn Davies, senior labour market analyst at the Chartered Institute of Personnel Development, said.

Food manufacturing and social care were among the parts of the economy that were most likely to be affected by a drop in EU workers, especially those from eastern Europe, he said.

This was echoed by the Food and Drink Federation, a trade body whose members employ 117,000 EU workers.

“The government must move swiftly to set up the new registration system and provide clear guidance to workers and businesses so that our valued EU workforce and those arriving during transition have the security they need,” it said.

While the number of EU nationals employed has decreased over the last year, overall employment growth in Britain has remained strong, easily outpacing forecasts in the three months to March.

“It seems that perhaps organisations have grasped the challenge and have become more adept at recruiting from the domestic workforce. The question of course is whether the quality of applicants is sufficiently good,” Davies said. The latest migration data are due on May 24. In February, the ONS said net migration of EU into Britain almost halved in the 12 months to September.

UK employment jumps but strong wage growth still elusive

British employers hired many more workers than expected in early 2018 but wage growth has yet to accelerate sharply, according to figures that leave the Bank of England still waiting for signs the economy is ready for a rise in interest rates.

Employment rose by 197,000 during the first three months of this year, the biggest jump since late 2015 and far exceeding the 130,000 consensus expectation of a Reuters poll of economists.

Sterling and British government bonds were little moved by the figures, which showed a familiar picture of solid growth in jobs, unemployment at its lowest level in decades, but only a modest pick-up in pay for most British workers, who have been hit by higher inflation since the 2016 Brexit vote.

Annual growth in earnings, excluding bonuses, edged up to 2.9 percent in the three months to March after a 2.8 percent rise in February, the Office for National Statistics (ONS) said on Tuesday, as expected in the Reuters poll.

While this was the biggest increase since the three months to August 2015, it represented only a 0.4 percent increase in pay in inflation-adjusted terms.

Including bonuses, total pay growth cooled to 2.6 percent from 2.8 percent in the three months to February, as expected.

Last week the BoE left interest rates on hold, despite saying in February that borrowing costs were likely to go up more quickly than it had previously thought. It said it wanted to be sure the economy was bouncing back after barely growing in the first quarter.

Economists said the strength of hiring in Tuesday’s figures suggested Britain’s economy did not have such a bad start to 2018 as portrayed by the preliminary official data.

“On balance, the combination of robust employment growth, falling unemployment and stronger underlying earnings growth, as well as a clear relapse in productivity in the first quarter, looks supportive to a Bank of England interest rate hike in August,” said Howard Archer, chief economic adviser to the EY ITEM Club consultancy.

“However, much is likely to depend on whether the UK economy sees clear signs of marked improvement over coming months.”

The ONS published new figures for employment of foreign nationals and for productivity, a long-term problem for Britain’s economy.

Output-per-hour fell by 0.5 percent quarter-on-quarter in the three months to March after a 0.7 percent rise in the fourth quarter of 2017, marking the biggest fall since late 2015 and denting hopes that British productivity was on the mend.

Less than a year before Britain is due to exit the European Union, the ONS said the number of EU nationals employed in Britain fell by 1.2 percent from a year ago to 2.292 million — the biggest drop in percentage terms for eight years.