Leo Varadkar announced his resignation this week
Leo Varadkar announced his resignation this week AFP

Simon Harris, who is set to become Ireland's youngest ever prime minister after being appointed party leader on Sunday, will be hoping his social media skills and fresh face can save his party's flagging fortunes as elections loom.

The 37-year-old, who the media has already dubbed the "TikTok Taoiseach" -- the name for the Irish prime minister, pronounced "Tee-shock" -- beats the previous record holder, his predecessor Leo Varadkar, who was 38 when he took the top job in 2017.

After Varadkar's shock resignation Wednesday, Harris jumped into the race to lead the centre-right Fine Gael party and become prime minister by default.

By Thursday lunchtime he had secured the endorsements of a majority of his party colleagues, prompting all other rivals to rule themselves out, and his coronation was confirmed on Sunday.

Harris told party members that he would repay their faith with "hard work, with blood, sweat and tears, day in and day out with responsibility, with humility and with civility".

His focus would be on "law and order", crafting a "more planned and sustainable" immigration policy and fighting "against the dangers of populism", said the incoming leader.

Harris's inevitable election as taoiseach when the Dail -- the Irish parliament -- returns from recess on April 9 crowns a meteoric ascent.

Born in 1986, he grew up in the small coastal town of Greystones near Dublin, the son of a taxi driver.

He dropped out of a college course in journalism and French in Dublin after one year to concentrate on an already promising political career.

Harris entered politics by campaigning for autism services for his autistic younger brother, and later founded a charity.

He joined Fine Gael's youth wing at the age of 16 and quickly rose through the party's ranks.

A county councillor aged 22, he was elected to parliament as a 24-year-old in 2011 -- at the time the youngest MP and titled "Baby of the Dail".

He was appointed health minister in 2016, aged just 29.

"In many ways, my career has been a bit odd... life came at me a lot faster than I expected it to," he told Hot Press magazine in a 2022 interview.

Harris served as health minister for more than four years, including during the Covid pandemic -- in which his communication skills were praised despite heavy criticism over nursing home deaths and occasional gaffes.

He can be an "awful old idiot at times" he said, after remarking that Covid-19 refers to 18 previous coronaviruses rather than the year it first occurred.

Harris was also embroiled in controversy over new hospital projects, while a threatened no-confidence vote by the opposition over overcrowding in wards led Varadkar to call a 2020 election in which Fine Gael slumped to third place.

A father-of-two and married to a cardiac nurse, Harris's prominence on social media, especially TikTok, has made him one of the most visible politicians in Ireland.

He has been higher education minister since 2020 and even critics concede he is a talented communicator.

With 1.4 million "likes" on TikTok, and hundreds of thousands of followers on both X and Instagram, Harris posts content almost daily to his audience.

But some of his videos and remarks have been seen as trying too hard to appeal to the younger generation.

During a stormy parliamentary committee meeting, Harris told the group: "Chillax -- I think everyone needs to take a step back here".

"All the young people know what 'chillax' is," he said in parliament the next day.

With his youth and slick communication skills his opponents jibe that he is "Leo 2.0", a continuation of a "metropolitan" style of politics that is out of touch with the wider electorate.

But for supporters, his enthusiasm could re-energise Fine Gael which still trails third in polls 10 weeks before local and European Parliament elections, and within a year from a general election.

"He has huge energy and huge ambition," one party colleague told the Irish Times paper.

"He's cute, crafty, and shrewd," said another.

Harris is a prominent user of TikTok
Harris is a prominent user of TikTok AFP
At 37, Simon Harris looks set to be Ireland's youngest taoiseach
At 37, Simon Harris looks set to be Ireland's youngest taoiseach AFP