TAOISEACH ENDA KENNY is to retire as Fine Gael leader, and step down as head of government.
He has led the centre-right Fine Gael party for 15 years and been prime minister since 2011.
Fianna Fail's Michael Martin is the current 1/2 favourite to be Taoiseach after the next general election with Leo Varadkar next at 9/4 and Simon Coveney priced at 6/1.
While Noonan and Kenny have been widely praised for their management of the economy, their Fine Gael party lost a quarter of its seats at elections previous year as voters complained they were not feeling the recovery.
Irish Prime Minister Enda Kenny conceded defeat on 27 February following elections that saw the governing coalition punished by voters tired of austerity, leaving the eurozone country in political limbo with no clear victor.
"Fine Gael came to power at a awful bad time for the country and had hard decisions to make".
In a statement on his way into a parliamentary party meeting on Wednesday evening, Kenny said he would continue as prime minister pending the election of his successor.
The small opposition Greens called for the new prime minister to be in place by the June 22 gathering of European Union leaders.
He made his decision public at lunchtime today along with a host of other ministers, including Richard Bruton.
I will continue to carry out my duties as Minister for Finance until a successor is appointed.
Athlone Senator Gabrielle McFadden has come out in support of Simon Coveney in the Fine Gael leadership battle, but her party colleage in Westmeath, Deputy Peter Burke, is backing Leo Varadkar.
Helen McEntee, another junior minister in Mr Varadkar's camp, said: "Look at the fresh new approach he has taken to politics, look at how he interacts with people, look at his vision for a more forward-thinking and open Ireland".
If elected party leader, Mr Varadkar said he wants to reach out to those who are not supporting the party and he also wants to make it a campaigning party.
Candidates for the Fine Gael leadership have been warned to sign up to a code of conduct to govern their behaviour in the campaign and they are also obliged to abide by data protection rules governing the use of membership details.