LONDON - A steady rise in the number of European Union migrants working in Britain stalled at the end of 2016, suggesting the Brexit vote, and the subsequent fall in the value of the pound, might have made the country less attractive as a place to work.

The number of non-UK EU nationals employed in Britain fell by 19,000 in the final three months of 2016 from the previous quarter, to stand at 2.24 million.

That was the biggest drop in any other October-December period since records began 20 years ago, official data showed. It compared with a rise of 12,000 in the same period of 2015 and a jump of 121,000 in the fourth quarter of 2014.

After a surge in immigration over the past 20 years, Britain has one of the highest proportions of non-native workers among European countries. Worries about migration were a big factor in last year's referendum vote to leave the European Union.

The rights of Europeans based in Britain, and of the estimated 1.2 million Britons living in continental Europe as of 2015, will need to be thrashed out during a complex two-year negotiating period that will start next month.

The last time there was a fall in non-British EU workers during the last three months of any year occurred in 2009, around the time of the global financial crisis. The previous time it fell in any period was in the third quarter of 2014.

The Office for National Statistics (ONS) said the data was not seasonally adjusted and should be treated with caution.

WAGE PRESSURES

The Bank of England is watching for signs of a slowdown in the supply of people coming into the labour force because it could push up wages and inflation.

Many employers have said they are struggling increasingly to find suitable candidates to fill their vacancies and are worried that a reduction in foreign workers could aggravate the problem.

The Chartered Institute of Personnel and Development, a human resources body, said on Monday that over a quarter of British employers believed that non-UK EU staff members might leave their firms or the country in 2017.

The value of sterling has fallen about 10 percent against the euro since the referendum.

"The figures offer further evidence that Brexit has had a discernible impact on the allure of the UK as a place to live and work," said Gerwyn Davies, the CIPD's labour market adviser.

"Employers in sectors that employ relatively large numbers of EU nationals, which also account for a sizeable proportion of vacancies, are likely to come under further recruitment pressures if, as we expect, this trend continues," he said.

The ONS's first overall official migration figures to cover the post-referendum period are due to be published on Feb. 23.

Its data released on Wednesday showed there was a small increase in the number of non-EU workers in Britain during the fourth quarter. But overall, the total number of non-UK nationals working in the country fell for the first time in a year.