La Cala de Mijas: They have lived on the Spanish costas for decades, often only learning the rudiments of the language, but since Britain voted to leave the European Union many British pensioners living in Spain are now heading back to school.

In a classroom at the Parnell Academy in La Cala de Mijas, a 20-minute drive along the coast from Marbella, a new breed of so-called “Brexpat” is cramming on the finer points of Spanish language, culture and history they need to pass Spain’s citizenship exam.

“It will be a wrench but if I have to give up my British nationality, I will,” said one pensioner, Margaret Nickolls, in front of her classmates who are all considering applying for Spanish citizenship to protect their lives in the sun.

Like many of the 300,000 registered Britons in Spain, Nickolls said she could not afford to await the outcome of potentially protracted divorce talks between the UK and the EU that will decide the status of expats like her.

Instead, she will opt for Spanish citizenship, which requires her to surrender her British passport, to ensure she and her husband, who has diabetes, retain access to Spain’s health care system.

“He has a series of pre-existing health conditions, including diabetes, which mean we cannot get private insurance out here,” she said of her husband.

The dash for citizenship has proved a boon for the school, with organisers saying they have received “hundreds” of inquiries for the crash courses. Richard Parnell, the school’s owner, hopes for a rush of applications, after only 540 Britons applied for citizenship in the decade to September 2015.

The test also covers sociocultural knowledge, including questions that would tax many a Spaniard. While most expats know who Rafael Nadal is, and some appreciate that Bunuel was a film director while Javier Bardem is an actor, the significance of the 1868 revolution (when Spain’s Queen Isabella II was deposed for an Italian prince) provokes a collective shrugging of shoulders.

“In a village near here, the test even asked applicants to identify the Big Brother celebrity Belen Esteban,” added Natasha Parnell, the academy’s director — a test of whether applicants were immersed in Spanish popular culture, which includes hours of reality TV. For many of those swotting in Marbella, giving up British citizenship is a difficult but necessary choice.

“I will change if I have to,” said Judy Browne, who arrived on Spain’s southern coast more than 30 years ago. “Before, I never got around to it but now I feel we are being treated like lepers by our own government.”

That sense of being abandoned by Brexit is strong despite hints from both Britain and the EU that citizens in situ before June 23 will be able to remain. Anne Hernandez, the teacher and founder of the association Brexpats in Spain, said she had fielded a deluge of enquiries about issues such as pensions and whether they will stay index-linked.

“It’s the elderly who are really confused and worried,” she said. “The women of 80 whose husbands have passed away and they have barely learnt a word of Spanish.” For many Britons, like Christine Meese, a 63-year-old widow, the safest option is Spanish citizenship.

“This is my country now, although I will always be British,” she said. “I was proud of my British passport because it used to mean something. If you got lost, it was a little treasure that could help you out. But it doesn’t have the same value today.”