One of the examinations tests applicants on their familiarity with Spanish society and culture. The other one determines their command of the Spanish language.

Applications for the first examination have grown significantly among British citizens living in Spain. Between January and June 2016, only 70 Britons took the test. But between the referendum and February of this year, that figure had risen to 423.

In theory, if you adopt Spanish citizenship, you must renounce your British nationality

Hilary Plass, university teacher

A similar picture emerges for the language examination: 50 applicants in the months before the referendum, and 281 between then and February. Most of the applicants in both cases are between 46 and 64 years old, and live in Madrid, Barcelona, Alicante or Málaga.

Michael Harris is a writer who lives in San Lorenzo de El Escorial, just north of the Spanish capital. He has been living in Spain since 1982 and now, at age 61, he has just passed both tests.

“I had never thought about it until I saw the results of the Brexit vote,” he explains. “As English citizens, we were just like any Spaniard except that we couldn’t vote in regional or general elections. Now, with Brexit, I am worried about losing my rights as a European citizen. And I want to remain one.”

Harris, whose wife is Spanish, is the vice-president of Eurocitizens, a group created by British residents in Spain to preserve their rights as Europeans.

Hilary Plass, who teaches English at Saint Louis University, an American educational center in Madrid, is also a British national. Plass, 63, has been living in Spain for the last 30 years, but has just taken the tests this year. She figures she won’t get her papers for another three years, though.

“Besides passing both tests, you have to prove that you have resided in Spain for 10 years in a row, provide your birth certificate, your British and Spanish criminal records, and take everything to the Civil Registry Office for evaluation by the Justice Ministry,” she explains. “I pay my taxes here, I have a life, a job and lots of friends here. I don’t want to be told in five years that I have to leave.”

Plass, who estimates that all the paperwork will cost her around €700, ventures that many British residents in Spain are unwilling to take the examination because they either speak no Spanish or don’t have the money.

I am worried about losing my rights as a European citizen. And I want to remain one

Michael Harris, writer

“There is no dual nationality treaty between Spain and the UK. In theory, if you adopt Spanish citizenship, you must renounce your British nationality, although in practice this does not happen. It’s nearly impossible to stop being British,” she laughs.

Anthony Luke, a 62-year-old journalist, has lived in Spain for 50 years. His wife is Spanish and his children were born in Madrid. Just like Plass, Luke says that what worries him the most is the uncertainty of what will happen after Brexit, although he says he is not extremely concerned because “there has to be a solution.”

“We hope to pressure both sides into including us in a special designation where we will not be considered foreigners,” he says. “But until then, it will be more convenient to have citizenship than to be asking for residency or work permits.”