The Progressive Democrat leader, Michael McDowell, who has lost his seat, has said he will resign from politics.
Mr McDowell conceded he could not close the gap with the Green Party Chairman, John Gormley, and said his career as a public representative was now over.
Mr Gormley was elected in Dublin South-East alongside Chris Andrews (FF), Lucinda Creighton (FG), and Ruairi Quinn (Labour).
Mr Gormley said he wished Mr McDowell and his family well for the future.
He said opinion polls were affecting voter behaviour and their role in elections should be looked at.
PD Senator John Minihan said it is an election which has seen the smaller parties squeezed out and his party leader was taking the brunt of the responsibility for his party's performance and being very hard on himself.
Irish people, he said, were not ready for someone like Mr McDowell who said things that people might not want to hear.
Senator Minihan said Mr McDowell has had a very colourful career and he is sad it is ending this way.
The Taoiseach, Bertie Ahern, has paid tribute to Mr McDowell. He described him as a tough and bright politician.
The Minister for Enterprise, Trade & Employment, Micheál Martin, said he was sad to learn of his cabinet colleague’s decision to resign. He said he will be a significant loss, calling him a very formidable parliamentarian.
He went onto say that he has made a ‘fine contribution to Irish life and it is very sad that he is bowing out at this stage’.
Before Mr McDowell conceded his seat, the Minister for Health, Mary Harney, said there was no question of reclaiming the party leadership from Micheal McDowell after what she has termed a 'tough' election for the PDs.
Ms Harney, who is at present the party's only TD to be re-elected, said that 'there is no question about taking back anything'.
'It's always a challenge for a party like ours...Clearly it was a tough election... on the government side people tended to be going towards FF...and on the opposition side they tended to go towards FG.'
The party's deputy leader and former Minister of State, Liz O'Donnell, has lost the seat she has held for 15 years, being excluded in Dublin South on the sixth count.
Earlier, Stephen O'Byrnes, a former press officer with the Progressive Democrats, conceded the party is likely to win just three seats, which he said was a disappointing result.