The number of people who applied for Irish passports from Britain in 2016 was 42% higher than the year before the Brexit vote, figures from the Irish government have shown.

The figures, released by Ireland’s Department of Foreign Affairs, show that in June the numbers were up by 9% on 2015. But by November the increase had risen to 106%, and passport offices in London and Edinburgh received 6,443 applications compared to just over 3,000 the year before.

An Irish passport. Photograph: Niall Carson/PA

Just under 65,000 people applied for an Irish passport in 2016.

Ireland’s minister for foreign affairs and trade, Charles Flanagan, described 2016 as “an exceptionally busy year for the passport service” and said he expected the trend to continue in the coming years.

The country’s London embassy was forced to take on extra staff last year to deal with the increase.

Irish citizenship rules are among the most accommodating in Europe. Anyone who has a parent who was an Irish citizen at the time of their birth is entitled to an Irish passport. Citizenship can also be claimed if one grandparent is, or was, an Irish citizen born in Ireland even if the applicant has no parent born in the country.

Applications from Northern Ireland, where residents in all communities are entitled to both an Irish and a British passport, rose by 27% to almost 70,000. Anyone born on the island of Ireland before 2005 is entitled to an Irish passport.

Following the EU referendum, Ian Paisley Jr, a Democratic Unionist party politician, urged constituents to get an Irish passport if they wanted one. “My advice is, if you are entitled to second passport then take one … take as many as you can especially if you travel to different world trouble zones,” he tweeted.