DUBLIN • A gay son of an Indian immigrant is now all but certain to become the next prime minister of Ireland, a country that has rapidly been leaving its conservative Roman Catholic social traditions behind.

Mr Leo Varadkar, who was chosen on Friday by the Fine Gael party to be its leader and, therefore, the head of the centre-right governing coalition, will be the first openly gay taoiseach (as Ireland's prime minister is called), and, at 38, the youngest. He succeeds Mr Enda Kenny, who is stepping down.

Mr Varadkar's rapid rise to the country's highest political office, only 10 years after he entered Parliament, owes much to a willingness to speak his mind, a novelty in the normally cautious world of Irish politics. Though in some ways he is emblematic of Ireland's transition to a more liberal society, Mr Varadkar presents himself as conservative on issues like the economy and law and order.

As he was campaigning for the party leadership, he used his Cabinet position as minister for social protection to start a high-profile campaign against welfare fraud, which was seen as a gesture to appeal to Fine Gael's right-wing supporters. He also surprised his liberal admirers by reaching out to the party's anti-abortion faction, saying that Fine Gael "should be a warm house for those who have socially conservative views".

In 2015, Mr Varadkar was widely praised for bravery and honesty when he said publicly that he was gay, the first Irish government minister to do so. At the time, Irish voters were debating a proposed constitutional amendment to permit same-sex marriage, and his stand is credited with bolstering the successful "yes" campaign, making Ireland the first country to legalise gay marriage by popular vote.

Mr Varadkar was born in Dublin in 1979, the son of an Irish Catholic nurse from County Waterford and a Hindu doctor from Mumbai, India.

He told The Irish Times in 2015 that he was raised Catholic but was "not a particularly religious person".

Mr Varadkar trained as a doctor and became involved in politics while still in medical school. He developed a reputation as an intelligent, hardworking and articulate city councillor in Dublin, won a parliamentary seat in the Dublin West constituency at the age of 28, and rose swiftly in party circles.

Though the Fine Gael party and its allies have the largest bloc of seats in Parliament, they do not command a majority. Even so, opposition parties are not expected to block Mr Varadkar's formal election this month as prime minister by the Dail. To do so would trigger a general election, which none of the major parties want right now.

NYTIMES