Taoiseach Enda Kenny has admitted he is personally disappointed after his Government suffered "a wallop" in a referendum to abolish the country's upper house of parliament.
Almost 52% of the public voted to keep the Seanad, in what was an embarrassing and damaging blow to Mr Kenny, who spearheaded a campaign to scrap it.
The No side emerged victorious with a margin of just 42,500 votes.
Mr Kenny said: "Sometimes in politics you get a wallop in the electoral process. I accept the verdict of the people."
The Taoiseach added that he welcomed the clarity of the public in what was the ultimate exercise of democracy.
"Naturally I am personally disappointed but I fully accept and respect the outcome," said Mr Kenny.
Just over 39% of the 3.1 million-strong electorate turned out to have their say on the historic move, which could have seen power handed exclusively to the Dail.
The Taoiseach said the Government would now reflect on how to reform the upper house to make sure it can contribute to Irish politics in "a meaningful way".
He insisted he had stuck with a promise he made four years ago to put the question of abolishing the Seanad to the people.
"The Seanad question was one element of a process of change and reform to politics that Government has been pursuing," Mr Kenny continued.
"Now that the people have made their decision and that they have decided and confirmed that the Seanad is retained as part of our constitution intuitions, I must now reflect upon what the best way that that can be made an effective contributor to the change in politics which I intend to continue within the Dail and in the wider sphere."
Elsewhere, Mr Kenny welcomed the outcome of a second referendum, in which 65.29% of the Irish public voted to create a Court of Appeal.
The Oireachtas is made up of the lower house, the Dail from which government operates, and the upper house, the Seanad.
The Constitution states that senators have no final say over new laws passed in the Oireachtas, but they do have the power to delay legislation by up to 90 days. The last time the Seanad used these powers was in 1964.
While its supporters have argued that senators can hold the Government to account, those who campaigned for its abolition had described it as a "toothless watchdog".
Tanaiste Eamon Gilmore suggested the 60 senators of the Seanad - whose jobs have been saved - could be tasked with shaking up the house themselves.
Unlike the Taoiseach, he said he was not disappointed by the result because he understands the Constitution "belongs to the people".
"The future of the Seanad will be considered by the Senate itself now," Mr Gilmore said.
"I think there will be discussion in the Dail and there will be discussion in the wider public."
The Fine Gael-Labour coalition was hit its hardest blow in the Dublin South-East constituency, where 61.3% voted to reject abolition, while the Taoiseach's home constituency of Mayo showed its loyalty to the Government, serving up the greatest Yes vote with 57.5%.
The Taoiseach's Fine Gael colleague Richard Bruton, who served as campaign director, called for a period of reflection to ensure political reform continues in the aftermath of the vote.
"Obviously the people are sovereign on this issue, this is their constitution and we fully accept their decision," he said.
"Political change in Ireland has always been difficult and there's been a history of people not to go with proposals.
"But we pledged that we would put this proposal to the people and we put it to the people and we sought to lay out the information the best we could.
"I think we ran a good campaign."
He joined the Tanaiste in rejecting claims the Taoiseach lost the campaign by refusing to debate the controversial issue, which he himself put to the people.
Elsewhere, Micheal Martin, leader of the opposition party Fianna Fail which campaigned against the Government, said the Taoiseach now has a duty to engage with other parties and civil society in a serious discussion about real reform of the parliament and Government.
But Sinn Fein's Gerry Adams - who backed the Government's Yes side - said the low voter turnout should be a cause of concern for all political leaders and the underlying causes analysed and addressed.
"All participants and parties involved in the referendum campaign were clear in saying that the Seanad in its current form is elitist, undemocratic and unacceptable," he added.
"This result cannot be viewed as a vote to retain the Seanad in its present form."
Political movement Democracy Matters, which campaigned for a No vote, said the Irish people had made a sovereign decision to stand up for their Constitution.
"We especially welcome the fact that, notwithstanding the Government's costly campaign, voters have rejected a cynical attempt to shut down alternative voices and further centralise power within our already dysfunctional political system," it said.