Leo Varadkar on Wednesday announced that he was stepping down as Ireland's prime minister and leader of the Fine Gael party in the governing coalition, citing "personal and political" reasons.

Pundits called the surprise move, just 10 weeks before Ireland holds European parliament and local elections, a "political earthquake". A general election also has to be held within a year.

Deputy Prime Minister Micheal Martin, leader of the Fianna Fail coalition partner, said Varadkar's announcement was "unexpected" but added that he expected the government to run its full term.

An emotional Varadkar, who is in his second stint as prime minister and at 45 remains one of Ireland's youngest leaders, said he felt he was no longer the "best person" to lead the country. 

"Politicians are human beings. We have our limitations," he said in a statement on the steps of Government Buildings in Dublin, surrounded by his Fine Gael cabinet colleagues.

"We give it everything until we can't anymore and then we have to move on."

Despite recent poor showings at the ballot box, Varadkar insisted that he believed the government could be re-elected.

But he added: "I believe a new taoiseach (prime minister) will be better placed than me to achieve that -- to renew and strengthen the top team, to refocus our message and policies, and to drive implementation."

"After seven years in office, I am no longer the best person for that job," he said.

"I am resigning the presidency and leadership of Fine Gael and will resign as Taoiseach as soon as my successor is able to take up that office.

"My reasons for stepping down now are personal and political, but mainly political," he said, without elaborating.

Earlier this month, Varadkar was widely blamed for a twin defeat, including the biggest-ever referendum loss by a government, on proposals to reform references to women, the family and care in the Irish constitution.

'Electoral loser'

Varadkar said his centre-right Fine Gael party would have a leadership contest, and that he would remain as premier until the new leader is elected, after parliament returns from recess next month.

Varadkar first became prime minister in June 2017. He was the youngest person to ever hold the office, Ireland's first openly gay prime minister, and the first to be from an ethnic minority background.

He stepped down as part of a deal with opposition parties after his party's poor performance in the 2020 general election, but took over for a second time in 2022 as part of the same agreement.

Varadkar, a pugnacious and sometimes controversial speaker in parliament, was in charge of Ireland's response to the Covid pandemic and during Brexit negotiations, where he helped prevent a hard border with UK-run Northern Ireland.

Fine Gael has lost five recent by-elections, leading some insiders to see Varadkar as an electoral liability. 

Ten of the party's lawmakers have announced that they do not plan to stand at the next election.

"His legacy will be that of an electoral loser. He promised to be a good communicator, but it turned out he was bad at it. He had no clear agenda, and delivered little," Eoin O'Malley, a political scientist at Dublin City University, told AFP.

In London, UK Prime Minister Rishi Sunak's spokesman said of Varadkar: "We wish him well on his next steps and we'll continue to work closely with him as a successor is sought."

Varadkar's potential successors include cabinet ministers Simon Harris (education), Simon Coveney (trade), and Helen McEntee (justice).

Political analysts said an election was not expected in the wake of the announcement, though opposition parties queued up to demand a vote.