Dan Boyle says the Green Party strategy is to get its candidates elected and the party will not be advising voters to transfer to Fianna Fáil or any other party.
Speaking on RTÉ's Morning Ireland, Senator Boyle said that despite being in Government, the Green Party has never had an election pact and this will not change.
Senator Boyle said it is up to party supporters to transfer their votes whatever way they wish.
He said that the European election involved parties electing candidates to different political groupings and that local councils had different arrangements between parties depending on the constituency.
When pressed about the Dáil bye-election, Senator Boyle said that such elections were notoriously difficult to win and that it was almost irrelevant what happened to second and subsequent preferences.
He said the party's attitude to being in Government was that that it was choosing to remain in Government and implement green policies.
Elsewhere, MEP Kathy Sinnott has begun her campaign for re-election in the South constituency.
She called on voters there to return an independent candidate as the constituency has done at each election since 1979.
Ms Sinnott said that as an independent she can bypass party politics and work solely for her constituents, in particular the disadvantaged, disabled and elderly in society.
Ms Sinnott was speaking after submitting her nomination papers to the returning officer for the constituency.
