Continental Europeans living in the UK are rushing to apply for British citizenship as they fret over the possibility of Britain voting to leave the EU in June, according to lawyers and community groups.

Many people are applying because they want to stay,” said Olivier Bertin, an elected member of the Assemblée des Français à l’Etranger, representing the interests of the French community in the UK. “Their life is in England.

Rose Carey, Head of Immigration at solicitors Charles Russell Speechlys, said her firm had experienced a significant increase in the past six to eight weeks in queries from EU nationals interested in applying for British citizenship.

We have seen lots of clients applying for British passports and naturalising as British, some who have been here for 20 years,” she said.

The impact of a British exit from the EU on the estimated 2.9m EU citizens living and working in the UK is unknown, as their status would be part of negotiations between the UK and Brussels.

Those who have worked in the country for at least five years automatically acquire permanent residence, but for those in the UK for less than five years, the outlook is uncertain.

Ms Carey said that, at present, EU passport-holders had the same rights as a British passport-holder.

It gives you the right to rent, to work, access to the NHS, access to benefits,” she said. “EU nationals moving to the UK for work need comply with no legal or regulatory requirements.”

In contrast, she said, a couple with two children seeking to move from the US to the UK would need sponsorship from a UK employer — which would in turn require a licence costing up to £1,500 — and could expect to pay in excess of £10,000 in legal fees.

Mr Bertin said one of his French friends in the UK had applied for British citizenship because her 17-year-old daughter was about to start university in the UK and she did not want to pay overseas tuition fees in the event of a Brexit.

A lot of French people who have been here for a number of years have decided to become British just in case because they wanted to vote,” said Patricia Connell, who runs the France in London website.

Nearly all EU nationals are allowed to apply for dual nationality in another EU member country, including France, Germany, Greece, Italy, Portugal and Spain.

The Home Office will not release data on the breakdown by nationality of citizenship applications in 2015 until May. Applications for citizenship rose 18 per cent to nearly 150,000 in 2015, before the EU referendum date was announced, although applications in 2014 were the lowest since 2004.

The Home Office would not comment on whether there had been an increase in British citizenship applications from non-UK EU nationals.

Article originally published in the Financial Times, March 21 2015