Uncertainties surrounding Britain's EU membership ahead of the crucial 23 June EU referendum has triggered a rush among EU nationals living in Britain to obtain a British citizenship. The number of applications for British citizenship by migrants rose to 5,245 in the fourth quarter of 2015 from 4,179 in the third quarter.

According to Home Office figures, which were released to The Times under freedom of information legislation, applications from Romanians and Bulgarians alone saw a 42% rise from 784 to 1,119 during the period. Applications from citizens of eight eastern European countries rose by 34% from 1,810 to 2,433; Polish nationals applying for citizenship rose from 1,145 to 1,590, French from 207 to 243, Hungarians from 217 to 303 and Bulgarians from 274 to 447.

The numbers started soaring since Prime Minister David Cameron began preparations for negotiations to secure a better European deal and the figure saw a rise by a quarter in the second half of 2015, according to a report in The Times.

People caught in the doldrums because of the upcoming EU referendum are seeking legal advice on their position if Britain comes out of the 28-nation bloc. Lawyers have also witnessed a surge in people approaching them on this issue. Kathryn Bradbury, partner at Payne Hicks Beach solicitors, reportedly told the newspaper that their firm "has seen a significant number of inquiries from EU citizens living in the UK over the last couple of months or so. There is a general disquiet over the uncertainty of the situation and some people are worried that they would have to leave the UK if the referendum vote went in favour of Brexit."

Currently, there are reportedly about 2.9 million people from other EU nations living in the UK and many are worried that a Brexit could mean a return of their work permits, scrapping of reciprocal health care arrangements, restrictions on studying in the UK and higher taxes on foreign property ownerships, the report noted.

For a migrant to qualify for a British citizenship, the person must have lived in the UK permanently for six years, passed the Life in the UK test and met language requirements of the country. Meanwhile, figures for EU nationals given British citizenship in 2014 show a decline from 2013 — a drop from 17,645 to 10,071.