Green Party European election candidate Saoirse McHugh has said she would resign from the party if they went into coalition with Fine Gael or Fianna Fáil.
If elected in Midlands North West, she would be the youngest MEP in the European Parliament.
Ms McHugh, who is from Achill island, was put on 12% in an exit poll after voting closed.
She told Gavan Reilly on Newstalk: "I think incrementalism in terms of climate action is done at the cost of support for more radical measures - and I just don't trust that Fianna Fáil or Fine Gael will implement a big, radical system change".
"Now if they do, wouldn't that be great".
She said that it "has nothing to do with me, that's just my opinion... it would be a democratic vote within the party as to whether we went in or not."
Asked if there was a vote that saw the Greens enter coalition with either party if she would resign her membership, she said "Yeah".
"I have not thought about this - I don't know why everyone keeps talking about it, there's been no general election even announced".
On winning a potential MEP seat, she said a 'PrimeTime' TV debate gave her impetus.
"I'd been knocking on doors before that but it had been hard to get - I suppose nothing really has the same reach as television.
"It was the first time I had the opportunity to reach that many people, so I knew it would change something anyway."
She was asked about how she may get from Achill to Brussels on sustainable transport.
Ms McHugh laughingly replied: "Oh you got me!"
"We've talked about moving over there - but yes, I will have to travel using unsustainable transport, Gavan".