Colin Farrell is campaigning for gay marriage rights in Ireland.
The Hollywood actor is putting his support behind a 'yes' vote in his native country because he believes in equal rights for the LGBT community and was dismayed when his openly gay brother Eamon had to go to Canada to legally marry his partner.
Writing in the Sunday World newspaper, he revealed: "The fact that my brother had to leave Ireland to have his dream of being married become real is insane.
"That's why this is personal to me. It's time to right the scales of justice here. To sign up and register to vote next year so that each individual's voice can be heard.
"My brother is now at home in Dublin living in peace and love with his husband of some years, Steven. They are about the healthiest and happiest couple I know."
Colin, 38, knew his older sibling was gay when he was at school and he admits he is very proud of the way Eamon faced up to homophobic bullies, even when they beat him for being attracted to men.
The 'Total Recall' star said: "I think I found out my brother wasn't grovelling in heterosexual mud like most boys our age when I was around 12. I remember feeling surprised. Intrigued. I was curious because it was different from anything I'd known or heard of and yet it didn't seem unnatural to me. I just knew my brother liked men and, I repeat, it didn't seem unnatural to me.
"My brother Eamon didn't choose to be gay. Yes, he chose to wear eyeliner to school and that probably wasn't the most pragmatic response to the daily torture he experienced at the hands of school bullies. But he was always proud of who he was.
"Proud and defiant and, of course, provocative. Even when others were casting him out with fists and ridicule and the laughter of pure loathsome derision, he maintained an integrity and dignity that flew in the face of the cruelty that befell him."
There will be a referendum on whether to make gay marriage legal in Ireland in the first half of 2015. It comes five years after same-sex couples were given the right to enter into civil partnerships with their partners.