Joan Burton has announced her resignation as leader of the Labour Party.
The former Tánaiste made the announcement at a press conference in the Royal Hibernian Academy in Dublin.
The move comes after Labour lost 30 seats in February’s poll - a disastrous result for the party following a tumultuous term in office.
This afternoon I informed my colleagues that I intend to step down as Leader of the party once my successor is elected. -@joanburton— The Labour Party (@labour) May 10, 2016
Ms Burton, who was elected leader after the resignation of Eamon Gilmore in 2014, said her resignation will take effect once her successor has been chosen.
Deputy leader Alan Kelly and Cork East TD Sean Sherlock are expected to put their names forward for the upcoming leadership contest.
It is understood that Brendan Howlin may stand, but only if his election is uncontested.
Under Labour rules leadership candidates must be nominated by a TD and seconded by a TD, limiting the options for candidates.
The contest is expected to last several weeks and all party members will be eligible to vote.
Bookmakers Boylesports installed Tipperary TD Mr Kelly as the odds on favourite for the leadership.
The Dublin West TD said she had asked the executive board of the party to immediately make arrangements for the election of a new party leader.
She told reporters she was honoured to serve as Labour leader for two years, and as deputy leader before that.
“In 2011, the people of Ireland asked the Labour Party to take on the responsibility of government during the worst economic crisis this State has ever known,” she said.
“Like most of the party, I entered government with both hope and fear in my heart - hope that with unyielding effort and sustained policy implementation we could turn things around; fear that the situation had already deteriorated to a point of no return.
“In the five years that followed, the Labour Party stood by the Republic, helping people back to work, safeguarding the social protection system against those who would have stripped it to the bone, building new schools across the country, and securing the funding for a new social housing programme – while all the time dealing with the morass of failed banks and toxic banking debt.
“In everything we did, our overriding focus was to bring about recovery so that families could face the future with hope rather than despair, and so that communities could once again prosper.
This afternoon I announced that I intend to stand down as Leader of the Labour Party. My full statement: https://t.co/RXJyco0Wnj— Joan Burton (@joanburton) May 10, 2016
"Despite February’s election result, I firmly believe we made the right decision in 2011.”
Ms Burton added that she was conscious “the recovery still hasn’t been felt in all homes” and that the party “couldn’t deliver quickly enough” for many people.
“We didn’t do everything right but I believe we left Ireland a better place than we found it – the true test for any party in government,” she said.
The Taoiseach, Enda Kenny, thanked the former Tánaiste for her work while in government.
He said: "On her retirement as Leader of the Labour Party, I thank Joan Burton for her work in government over the past five years, both as Tánaiste and as Minister for Social Protection.
"During this time, she and her ministerial colleagues in the Labour Party played a major role in rescuing the Irish economy, which was on the brink of collapse when we entered government in 2011. Many of the tough decisions that had to be taken to turn the country around were unpopular and politically difficult but Joan Burton and her colleagues were steadfast in doing what was right for the country.
"In her role as minister, Joan Burton spearheaded many of the welfare reforms that helped the last government to surpass our job creation targets to the point where the unemployment rate has been reduced from over 15% to 8.4%.
"I would like to wish Joan Burton, her husband Pat and family every success and happiness in the future."