LONDON (Reuters) - Net migration of European Union citizens into Britain fell to its lowest level since 2012 in the year to March, but this was more than outweighed by a record influx of non-EU citizens ahead of Brexit, official data showed on Thursday.

FILE PHOTO - The Tower Bridge is seen in London May 23, 2007. REUTERS/Alessia Pierdomenico (BRITAIN)

The Office for National Statistics said 87,000 more EU citizens moved to Britain than left it during the year to March 2018, down from 123,000 a year ago, marking the lowest net migration figure since the year ending in December 2012.

Net migration of EU nationals into Britain has fallen markedly since voters, many motivated by a desire to reduce immigration, opted to leave the bloc in a June 2016 referendum.

Business groups, however, worry that companies will find it harder to hire the staff they need.

“These figures are nothing to celebrate, and given businesses are facing record skills gaps at every level it’s disappointing to see the decline in people from Europe coming here to work,” Jane Gratton, head of business environment and skills at the British Chambers of Commerce, said.

Thursday’s data showed more EU nationals from the eight east European countries that joined the EU in 2004 left Britain than entered for the first time in records dating back 10 years.

Romanians and Bulgarians -- who have only had an unrestricted right to work in Britain since 2014 -- accounted for more than half of net EU migration to Britain.

Overall net migration into Britain rose to 271,000 in the year to March, up 28,000 on a year ago.

That reflected net migration of 235,000 non-EU nationals -- a record high.

But the ONS said that “an unusual pattern of non-EU student immigration” had affected the figures for the year to March 2017, making meaningful comparisons with the latest year difficult.

“Longer-term trends should instead be considered,” the ONS said. Net migration of non-EU nationals into Britain has been on a steadily rising path since the year ending December 2015.

Britain’s government has said it is committed to bringing net migration into Britain down to the tens of thousands.