Brexit is turning the UK into a country of dual citizens. An Irish grandparent is now the most prized possession in the land, giving the proud owner the right to an Irish (and thus an EU) passport. Applications for Irish passports are surging – 200,000 Britons applied in 2018. About half of these were from Northern Ireland – anyone born on the island of Ireland before 2005 and anyone born there since with a parent who is Irish, British or “entitled to live in Northern Ireland or the Irish state without restriction on their residency” is entitled to Irish citizenship. The other half are Britons living outside Ireland who have suddenly discovered an affinity with the birthplace of a parent or a grandparent. The number of applications has doubled since the referendum, with by far the greater increase coming from outside the island of Ireland. That burgundy passport is now extremely highly prized.

Neale Richmond, the chair of the Irish Seanad’s Brexit committee, has claimed that at least 10% of the British population outside Northern Ireland are eligible for an Irish passport. It is a captivating statistic that is almost impossible to verify, but if it is even vaguely true and Brexit goes badly, we can expect the number of Irish citizens to swell significantly in the next few years.

My family is contributing to this: my son, through my wife, has an Irish grandmother and has claimed Irish citizenship. This year, he may visit his new homeland for the first time. His grandmother, who was born near Cork, came over to join the war effort against Hitler and never returned. Eighty years on, her daughter and grandson retain a foothold in the EU and a place in the postwar vision of a unified Europe.

‘Ireland will give me the freedom to be who I want to be’ ... John Gribbon outside parliament for the Brexit vote on 15 January. Photograph: John Gribbon

The Mosses are not alone. Indeed, the pursuit of dual nationality by Britons disaffected by Brexit or seeking to protect their residential, health or working rights is happening all over Europe. When we asked Guardian readers who have applied for citizenship elsewhere to get in touch, more than 1,100 people replied. Many were applying for Irish, German, French, Belgian and Swedish citizenship, but plenty of other countries were represented, including Austria, Cyprus, Denmark, Hungary and Malta. There were a surprising number of applications for Latvian citizenship, some from descendants of Latvians who fled to the UK following the Soviet takeover of their country in 1944.

John Gribbon, an IT manager who lives and works in England, is one of the hundreds of thousands who have become Irish recently – his citizenship was granted in 2018. “I wanted the opportunity to work wherever I chose in Europe and did not welcome the fact that the opportunity had been removed by the Brexiteers,” he says.

Gribbon’s grandfather, who died in 1964, was born in Belfast in 1915, served in the British army and worked as a sheet-metal worker in the Tyne shipyards. He had nine children and “lived for their freedom and opportunity”, says 46-year-old Gribbon, who has become an Irish citizen to preserve his own freedom and opportunity. “I had the Willy Wonka ticket 100 years later,” he says. “Although I never met him, his parting gift, being an Irishman, was the best present I could ever have. England was my past and will always be part of me as it’s who I am, but Ireland will give me the freedom to be who I want to be.”

‘I finally have the guarantee of the same freedom of movement and security that I had for the previous 40 years’ ... Karen Stone, the artistic director of the theatres and orchestra of Magdeburg. Photograph: Andreas Lander

Matt Hurley, a 22-year-old Earth sciences master’s student at Utrecht University, became an Irish citizen in 2017. “I have always felt that I was Irish, as my father is Irish, while my mother was born in England to Irish parents,” he says. “I had never contemplated getting Irish citizenship, as it felt like I was taking something from a country I have never contributed to.” But now, he says: “Britain no longer feels like home, as it has rejected Europe and I have not.” Of course, there are also practical advantages: “Getting an Irish passport has enabled me to live abroad without the worry of my tuition fees being increased to the same level as non-EU students or having to apply for some kind of student visa.”

The statistics on Irish dual citizenship are particularly notable because the number of Britons eligible is far higher than for any other country and the process of applying is straightforward – automatic and free citizenship for children of people born in Ireland on production of the relevant birth documents; a fee of about £250 (£130 for children) to get yourself on the Foreign Births Register if you were born outside Ireland but have an Irish grandparent. However, the same pattern is apparent throughout Europe (except in Spain, which doesn’t permit dual citizenship for Britons resident in the country – one reason why so many British expats in Spain are likely to return in the event of a no-deal Brexit – and Poland, which will allow dual citizenship but not formally recognise a second citizenship within its own jurisdiction). The number of UK citizens who applied for German citizenship, for instance, more than doubled in 2017 compared with 2016, rising from 2,865 to 7,493. The number of Britons applying to become German is more than 10 times greater than before the 2016 referendum.

One remarkable result of the EU referendum is the number of people whose families fled the Nazis who are now reclaiming German citizenship. “I was born in Palestine in 1944, the child of stateless German-born refugees who had been deprived of their citizenship because they were deemed to be Jewish,” says Nancy Krauss, a retired doctor in East Anglia. “I was brought up only speaking English because my parents wanted us to feel as though we belonged to the UK. I am now applying for German citizenship alongside my British citizenship. The spur was Brexit. German citizenship will allow me, my daughter and grandchildren to remain European, which gives us more options if things get very difficult in this country. Underlying that, though, is a sense of righting a wrong, returning to the roots – at least mentally – that belonged to my parents and of which they were unjustly deprived. If the German government now wants to make amends, I welcome that.”

‘For my kids, Brexit is incomprehensible’ ... Peter Tuck on the French-German border. Photograph: Peter Tuck

Germany is extremely popular because it ranks third (with France) on the Henley Passport Index, which ranks countries by the number of destinations passport-holders can visit without having to arrange a visa. Ben Wright, a 51-year-old management consultant who lives in Germany with his wife and family, has just become a dual citizen. “I’ve spent the past 25 years working, living and travelling across Europe,” he says. “I’ve seen walls come down and barriers to movement fall. Brexit is offering blue passports. That doesn’t disguise the fact the passport is being devalued.” Wright blames Theresa May. “The Brexit vote was not the major issue,” he says. “It was May’s decision that the UK would leave the single market and the customs union. That makes a new passport essential, in case I want to work in Switzerland or elsewhere in the EU.”

Karen Stone, the general manager and artistic director of the theatres and orchestra of Magdeburg, waited barely a day after the referendum to start her application for dual citizenship. “It took a year, huge amounts of paperwork, an exam to prove that I was fluent in German and another on the German law and constitution,” she says. “The whole thing cost around €1,200, but now I finally have the guarantee of the same freedom of movement and security that I had for the previous 40 years.”

Like many people who have lived abroad for a long period, she is furious that she was not allowed to vote in the referendum because she had lived outside the UK for more than 15 years – the cut-off for eligibility. “I hope that, should there be a second referendum, this decision would be reviewed,” she says.

The number of Britons applying for Dutch, Swedish and French citizenship has risen enormously, too. In the absence of any progress on Guy Verhofstadt’s idea to offer Europe-minded Britons associate citizenship of the EU, those who qualify – by birth, marriage or residence – for another European country are taking matters into their own hands.

‘My national identity used to be hugely important to me. Now I am embarrassed to be British’ ... Beci Clayton with her husband, Vincent. Photograph: Beci Clayton

In France, Beci Clayton was quick to apply after the referendum result, worried that if she did not her family would find themselves in difficulties. The 35-year-old English teacher lives in Brittany and is married to a French man; her two young children are dual nationals. “I had always thought we would return to the UK; I no longer know if that will be possible, but at least I know that my family will be able to stay together in France. I will be able to live and work in France indefinitely and this is a great relief for me. My national identity used to be hugely important to me. Now I am embarrassed to be British and feel quite lost.”

Peter Tuck, a 45-year-old vet in Grosbliederstroff – which sounds German, but is in north-eastern France, right on the border of the two countries – is in a similar situation. “I moved to France in 2002 with my German wife and we have been living here ever since. Our two children were born in France. We live in France, but our children cross the border every day to go to school in Saarbrücken,” he says.

“After the referendum, we went through the French naturalisation process quite quickly. For us, freedom of movement is a joy and a privilege. Our region is completely dependent on the border being open and invisible and we can’t imagine anyone wanting to reintroduce checks that have been removed. For my kids, Brexit is incomprehensible.”

James Reynolds is a 38-year-old teacher at an international school in Staffanstorp, Sweden. Married to a Swedish woman and with a two-year-old son, he was worried about his family’s rights in the event of a no-deal Brexit – and about the rules regarding income levels for spouses if he wanted to relocate to the UK. “I have decided most probably never to return to the UK, as my family doesn’t feel welcome,” he says. “This is a shame, as I’m a UK-qualified teacher with 15 years’ experience, although it has to be said that teaching in Sweden is far less stressful than in the UK.”

Romit Jain, a 43-year-old Londoner of Indian heritage, is another Briton who has successfully sought Swedish citizenship. “I applied within a week of the referendum and was granted citizenship within four weeks,” says Jain, who works for a Swedish company and is currently based in South Africa. “I was eligible for Swedish citizenship because I am married to a Swede and had been living there for about five years. The process went incredibly smoothly and I even got a nationality certificate in the post. My wife doesn’t have one of those, so I joke that this makes me more Swedish than her.”

Britain no longer feels like home, as it has rejected Europe and I have not Matt Hurley

Jain embodies the ludicrousness of May’s denigration of “citizens of nowhere”. “Swedes used to ask me, before the referendum, if I would take Swedish nationality, because I was eligible anyway,” he says. “I always answered that I didn’t need it and I saw it as a practical question, as opposed to one about identity. But after the referendum I realised that it is about identity as well. I feel Swedish and British, European and Indian. I don’t see that as contradictory, although England versus Sweden in the World Cup was tricky.”

Some people didn’t even wait for the referendum result before they started the process of getting a second passport. Richard Ventham, a 44-year-old who works in the pharmaceutical industry, began investigating dual citizenship when David Cameron announced he would hold a referendum. Having lived in Belgium since 2003, he says: “I couldn’t trust the xenophobic British public to make the right decision. I became Belgian in March 2016 and haven’t had a sleepless night since. I’m European – and no xenophobic, closed-minded, small majority can take that away from me.”

Ventham is rather more emotional and committed a European than most of the bloodless technocrats who argued for remain in 2016. He describes the potential loss of freedom of movement as a “tragedy”. “My wife and children are Belgian. I suppose some people think I jumped the gun to apply prior to the referendum, but I could read the runes and the hysteria in the tabloid newspapers and wanted my status assured. I cling on to hope of a second referendum to reverse the decision, but as I’ve lived in Belgium for more than 15 years I’m no longer eligible to vote in it. I’ve been disenfranchised.”

‘I feel Swedish and British, European and Indian. I don’t see that as contradictory’... Romit Jain. Photograph: Romit Jain

Oliver Gompertz, a pilot based in London, is applying for a Maltese passport. “People often scoff and ask: ‘Is that the one you can just buy?’” he says, referring to the countries that offer a fast track to permanent residence and sometimes citizenship if applicants are willing to make a substantial investment in the country. “But I’m entitled to it through my grandparents.” It has not, however, been a straightforward process: “I started assembling the documentation required more than three years ago and then it was a question of getting appointments with the embassy in London, which took about six months, and then waiting for your application to be processed, which took another 18 months. Then you need another appointment to get your passport.”

He believes it will be worth it. “It’s partly about career security,” he says. “But for me it’s mainly about how I feel about my identity. When you go to the US, Canada, Australia, New Zealand – crossing the border, you’re made to feel like an outsider because you don’t have the right to be there. I don’t want to feel like that going to Europe.”

For many people, it is a practical issue, too. Jane Johnson, a 55-year-old academic in Bologna, Italy, has just completed an application for Italian citizenship. She was motivated, she says, in part by fear of losing “access to the wonderful state health service in Bologna”.

But I believe Gompertz’s more emotive argument resonates. For almost 50 years, despite the half-heartedness of the British political class, we have been citizens of Europe, with unfettered access to that beautiful, varied, culturally rich continent. Some part of us could claim to be French or Spanish, Italian or German. We had fought many wars with our neighbours; now we could enjoy a long peace and claim a stake in their wonderful countries.

Brexit may change this for ever. While my wife and son are safe in their new nationalities, the angry Welshman in our family – me – is about to lose his EU passport and the fantasy that he is Spanish. Is this really the end of the dream? If I set up a small business in Plovdiv, how long will it be before I qualify for Bulgarian citizenship?

Some names have been changed

• This article was amended on 7 February 2019 to more accurately set out the position on dual citizenship in Spain and Poland.