DUBLIN (REUTERS) - Thousands of kilometres from home, Dubliner Mark Govern watched in Sydney as Ireland's referendum on gay marriage dominated discussion.
Three weeks ago, he made a big decision.
He cleared his bank account, forked out to take extra annual leave from work and bought a A$1,600 (S$1,688) return ticket in the hope of helping Ireland - a predominantly Catholic country - do what no other country in the world has done, approve same-sex marriage in a national vote.
"It's a once in a generational chance," said Govern, a gay man who campaigned to extend civil marriage to same-sex couples before he took a career break to move to Australia last August.
"I felt that if this didn't pass and I could have come home and contributed in some way, I'd spend the next 30 years regretting it."
Govern, 31, is one of hundreds or perhaps even thousands of Irish people returning home to vote, according to Joey Kavanagh of Get The Boat 2 Vote, one of a number of groups encouraging Irish men and women abroad to come back and cast their ballot.
More than 180,000 Irish nationals, equivalent to 8 per cent of the 2.2 million who voted at the last election, left the country in the four years to the end of April 2014 as Ireland's economic crisis sparked a wave of emigration.
With the economy recovering, some say Friday's vote could decide whether they eventually return for good.
"It depends what kind of Ireland it is. If we're going to keep voting no to these kind of things, I don't know," said Tara O'Donnell, 25, who has booked a flight back from Brussels and knows at least 30 friends and colleagues who have done the same.
Others are flying in from Canada, New York, Thailand and from across Europe, said Kavanagh, whose group supports a "Yes"vote.
Ryanair's 16 flights from London to Dublin on Friday have been booked out for days.
While surveys predict the referendum will pass by as much as two-to-one, pollsters say it might hinge on younger voters actually turning up to vote.
Kavanagh says those returning home are overwhelmingly "Yes" voters.
Ireland is one of few countries in the European Union that does not allow its emigrants to vote via postal or embassy ballot.
Those abroad for less than 18 months remain eligible, but only if they turn up at their local polling station.
In Brussels, O'Donnell said, "It affects so many of my friends, I would just feel awful if I didn't come home."
"There was no way I'd miss this vote, not for the world. It's definitely the most important vote I've ever had a chance to vote in."