The Taoiseach has said it will be "challenging" for Fine Gael to keep its European seats in June's elections.
Leo Varadkar also said it will be "hard to achieve" the success of 2019's European elections, which saw his party win five seats.
Fine Gael will be down two sitting MEPs for the campaign, with Frances Fitzgerald and Deirdre Clune announcing they will not be running for election.
Speaking in Boston, Leo Varadkar said the European elections will be a battle.
"They're goig to be challenging. Even though it was not said at the time, we had an extremely good local and European elections last time.
"Five seats in the European Parliament, 29 per cent of the vote, more than Fianna Fáil and Sinn Féin combined. We got about 25 per cent of the local elections [votes], and increased our number of candidates which is rarely achieved by a party in government.
"So it's going to be challenging to hold what we have, but of course that's the objective."
MEP Seán Kelly, John Mullins, who served as the CEO of Bord Gáis between 2007 and 2012, and Senator Regina Doherty have been confirmed as Fine Gael candidates for the European elections.
Sitting MEPs Colm Markey and Maria Walsh have also said they intend to run again.
