London - From looking up their European ancestry to seeking out a continental soulmate, some Britons are leaving no stone unturned in their bid to keep ties with Europe after the nation's vote to leave the union. So far, nobody knows whether British citizens will face curbs on living and working in the European Union post-Brexit, but the uncertainty has led many with as-yet-unfulfilled claims to both British and EU rights to file their paperwork.The easiest way to obtain an EU passport is through an ancestral link to a country within the bloc and Ireland is the most likely choice for Britons.An estimated 10% of British citizens have claims to Irish citizenship, which can be granted to grandchildren of its citizens."Before the referendum, I was thinking about applying for Irish citizenship, but I wasn't going to do it unless we voted to leave because I felt it was dishonest," journalist Johanna Derry told AFP.Since the vote, Derry has gathered the documents needed to be placed on the Irish foreign birth registry, opening the way for a full application."I feel like I'm European, so in order to stay European... it just makes sense," she said."I have been accused of maybe betraying my English roots... but I have so much Irish culture in my family life that it doesn't jar with me."Such was the demand for Irish passports in the wake of the June 23 shock vote that Ireland's foreign minister Charlie Flanagan pleaded for a slowdown, warning consular offices were under "significant pressure".Unearthing the family tree Meanwhile, Germany's embassy in London told AFP there had been "a spike in information requests regarding German citizenship" immediately after the vote.More surprisingly, around 400 British Jews whose ancestors were forced to flee Portugal five centuries ago were reported to have applied for citizenship in the southern European country."We are receiving a dozen requests a day," Michael Rothwell, a spokesperson of the Jewish community in Porto, told AFP.Until the Brexit vote, only five Britons had applied for Portuguese citizenship under a law passed in March 2015 offering Sephardic Jews nationality as a form of reparation for the persecution their ancestors suffered.Family tree finding website ancestry.co.uk said it had reported a "significant upturn" in people researching their family history following the referendum result."Ancestry has seen trial memberships for new users go up 40%," said Sue Moncur, UK manager for the website."At the same time searches for Irish records have gone up by 20% week on week," she added.'Find love over Brexit'For those without a genetic claim, love could be the answer.Britons with EU spouses will retain the right to live and work on the continent under EU law, although the right to citizenship is up to the individual country.To give matters a helping hand, British students Katy Edelsten and Chloe Cordon have set up a dating site called Idbenothingwithouteu.co.uk, which aims to "match up as many lovely couples as possible, who we hope will fall so madly deeply in love that they can't help, but get hitched".The website has attracted thousands of members and its creators hope to extend the service for concerned Britons living on the continent."Nobody wants to get married just for a passport," Edelsten told AFP. "It's just another fun way to date at the moment when there's all these other ways, so why not find love over Brexit."Our ultimate goal would be for some people to actually fall in love and then we can have an en-masse wedding, with EU rings and wedding cakes."