More than 13,000 British people requested a new nationality from an EU member country in 2017, the BBC has reported.

The figure is a massive increase compared to 2016 (5,025) and 2015 (1,800). The UK will leave the EU in March 2019.

Currently, there are some 2.5 million citizens from across the European Union living in the UK, and there are another 1.5 million British citizens who have made their homes in the EU, with some 700,000 of those living in Spain alone.

The BBC has acquired data from 17 EU countries. German nationality is the most popular among British people: 7,493 British people became German nationals last year.

France is the second most popular country for British people wanting to keep their EU nationality (1,518), followed by Belgium and Sweden.

Last year, 1381 Britons became Belgian nationals, according to data from the Belgian Statistical Office, Statbel.

According to the Statbel figures, the number of Britons seeking Belgian nationality has increased tenfold since Britain’s decision to leave the European Union.

After Brexit, Brussels has seen a steep surge in nationality requests from British residents. The UK’s departure from the European Union has yet to be technically started, but British residents in Brussels are wasting no time in looking into the possibility of becoming Belgian citizens in order to remain in the EU.

There are some 200,000 Brits living in Belgium. It appears that many of them are very worried by the consequences of the Brexit, and some started asking for Belgian citizenship.

Most of the applications come from Britons who have been resident in Belgium for years and want to acquire Belgian nationality because of the uncertainty about the aftermath of Brexit.

To become Belgian nationals, they have to submit an application in the municipality where they reside and pay the sum of 150 euro. They also need to prove that they have been residing legally in the country for at least five years and that they are “socially integrated”.

Applicants can prove their “social integration” mainly by showing that they are working in Belgium. They can also take an integration course, but only 30 did so in 2017.

Britons who are awarded Belgian citizenship may keep their British nationality. In  most cases across the EU, those involved have also retained their British citizenship and so have become dual nationals.