Fianna Fáil leader Micheál Martin has said that his party will not oppose the nomination of Enda Kenny as Taoiseach, breaking the tradition of the opposition backing their own candidate.
Deputy Martin said it was clear that Fine Gael and Labour had received a mandate from the people, and his party would not support any other candidate.
"‘We will not follow the example, set in recent years, of manoeuvring to oppose everything for the sake of popularity," the Fianna Fáil leader said.
Mr Martin said Fianna Fáil would provide "constructive opposition" in the Dail.
He pledged not to oppose everything for the sake of popularity.
“It is my intention that Fianna Fail will provide an opposition that is both assertive and constructive,” he said.
Mr Kenny was nominated by Fine Gael's Simon Harris, youngest of 166 TDs at 24, who said "the period of mourning was over" for Ireland.
The nomination was seconded by Labour's Ciara Conway.
However the nomination of Kenny was opposed by Joe Higgins of the Socialist Party, one of the nominated speakers of the 16-member technical group of Independents.
Flanked by independents and left-leaning TDs, he claimed the Fine Gael/Labour coalition’s programme for government was a “grotesque betrayal” of the democratic revolution of the people.
“A vote for Deputy Kenny as Taoiseach is a vote not for revolution, not for change, but for counter-revolution and more of the same,” he said in an impassioned address.
He warned the programme of “savage austerity” would not go unchallenged.