John Gormley, the leader of former junior coalition party the Greens, said it was a sad day for the party.
"We have suffered a major defeat, but the party will regroup, we will continue. We're a party with a set of beliefs and values and a vision for the future," he said.
"We have great people here. We're going to rebuild this party.
"It has been a very difficult period over the last number of years. We've been associated with a government that had to make very difficult decisions and as a result we have had to endure this defeat."