He is due to make the announcement in a planned photocall at noon today.
Taoiseach Leo Varadkar is to stand down as Taoiseach and Fine Gael leader.
He will make an announcement at noon today in the courtyard of Government Buildings.
Leo Varadkar first became a county councillor when he was co-opted to Fingal County Council in 2003. He went on to win a seat in the 2004 local elections, after an unsuccessful bid five years earlier.
In 2007, he became a TD for Dublin West constituency, and was appointed to the Fine Gael front bench.
He became a Government minister in 2011 during Enda Kenny's time as Taoiseach, despite being in opposition to his leadership the year before.
He became the first openly-gay serving cabinet minister in Ireland when he came out in 2015, ahead of the Same Sex Marriage referendum later that year.
He served in various ministries before succeeding Enda Kenny as Taoiseach in June 2017.
One of the high points of his time as Taoiseach was the success of the referendum to repeal the 8th Amendment in 2018.
He led Fine Gael in the General Election in February 2020, where the party lost 15 seats and were unable to form a government.
He led the care-taker government through the start of the Covid-19 pandemic, before forging a historic three-way coalition government with Fianna Fail and the Green Party, which saw Micheal Martin take up role of Taoiseach before Leo Varadkar took over in December 2022.
Most recently his government suffered a double-defeat in the Family and Care referendums at the start of the month.
He had returned from the US and a St Patrick's Day meeting with Joe Biden in Washington last week, before announcing his resignation earlier today.

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