Varadkar: A historic prime minister for Ireland

As a gay man born to an Indian father, Leo Varadkar would probably never have become Ireland's prime minister a generation ago, but a transformation of Irish society has propelled him to success.

At 38, Varadkar will also be Ireland's youngest prime minister when parliament is set to confirm his nomination this month, after a meteoric rise to the head of the governing centre-right Fine Gael party.

He went public about his sexuality a few months before a landmark referendum in 2015 in which Ireland became the first country in the world to vote in favour of same-sex marriage in a referendum.

"I am a gay man. It's not a secret, but not something that everyone would necessarily know," he said in an interview with national broadcaster RTE.

"It's not something that defines me: I'm not a half-Indian politician, or a doctor politician or a gay politician for that matter," he said, adding that he just wanted to be "honest with people".

"It's just part of who I am. It doesn't define me -- it is part of my character I suppose," he said.

The influence of the Roman Catholic Church in the traditionally conservative country has waned in the wake of a series of child abuse scandals in Ireland, which decriminalised homosexuality only in 1993.

But there are limits to the country's newfound tolerance, and early in his campaign for the party leadership Varadkar said he hoped his sexuality would not be an issue.

He also said that if elected he would not expect his partner Matt Barrett, also a doctor, to accompany him on official business.

- 'X Factor Leo' -

Varadkar was born on January 18, 1979, the son of a doctor from Mumbai who married an Irish nurse he had met in Britain.

He and his two older sisters were raised in Dublin and went on to attend Trinity College in Dublin, where he studied medicine.

Although a qualified doctor, he became a councillor in his early twenties and has been a full-time politician since he was first elected to parliament in 2007.

Currently the minister for social protection, Varadkar has held various cabinet posts and garnered a reputation as a rightwing straight-talker.

But while attracting supporters he has also attracted more than his fair share of controversy, and is regarded as sharply intelligent but socially awkward.

In 2008, when unemployment was running high after a catastrophic economic crash, he was widely accused of racism for advocating payments to unemployed immigrants who agreed to return to their countries of origin.

More recently, after championing a campaign against "welfare cheats", he said he wanted to lead a party for "people who get up in the morning", prompting accusations that he was pushing the country's centrist consensus sharply to the right.

But he is popular with supporters who have dubbed him "X Factor Leo" for his telegenic image.

Opinion polls suggest that he will boost Fine Gael's ratings, and while he has ruled out an early general election, speculation is growing that the man who shoots from the hip might not be able to resist.