Stephen Fry, Michael Sheen and the other high-profile people backing the Yes vote in the Irish gay marriage referendum

Stephen Fry has spoken out in favour of gay marriage as Ireland goes to the polls to vote Yes or No in the referendum.

Fry joked: "I don't know if I'm in favour of gay marriage, myself. My husband is, and I'm half Irish."

Fry married his partner Elliot Spencer in January this year.

Backed by his QI co-presenters, including Alan Davies and Jimmy Carr, Fry said in Gaelic: "I want the same happiness that I have found to be afforded to those in Ireland too. Give people a chance to marry, and have their love celebrated."

He continued: "I mean in the kindest way possible to try and connect with you all because so many of us in Britain are thinking of you and this referendum that's coming. It's a chance for Ireland to make an extraordinarily proud noise in the world."

Jason Byrne and Aisling Bea made the comedic video "in the hope that people will back our battle for equality and for civil rights".

Sports personalities including footballer Robbie Keane and former rugby player Brian O'Driscoll have also endorsed the Yes vote. Keane said it would "show the world that Ireland is a compassionate country."

Former president Mary McAleese, who has spoken out about how her devout Catholic son was bullied for being gay, has also backed the Yes campaign.

Author Marian Keys praised the Irish expats who came home to vote in the referendum, and urged them to back gay marriage.

Michael Sheen and his partner Sarah Silverman both tweeted in favour of gay marriage.

Graham Norton, who has spoken of feeling out of place growing up gay in rural Ireland, has also backed the Yes vote.

Comic Trevor Noah joked that gay people deserved to be just as unhappy in their marriages as everybody else. He said: "My honest advice to you, is to take this opportunity to give them the same pain and suffering every other married person has. Why should gay people have all the fun?"

Other comedians, including Jack Dee, Russell Kane, Sean Lock, Rich Hall, Rob Beckett, have also backed the Yes vote.

In April, Mrs Brown of Mrs Brown's Boys fame urged people to "grow up" and vote Yes.

"Any two people who feel in love enough should be allowed to get married," the character argued. "What's the fecking fuss?".

Opposition to gay marriage has been much more muted on social media.

However, the possibility of a "shy" No vote has been touted. Echoing the theory of the shy Conservative vote in the UK General Election, in which people intending to vote Tory didn't tell polling agencies, because they don't want to be painted as regressive.