John Bryan had been widely expected to stand in Carlow-Kilkenny
The former president of the Irish Farmers' Association (IFA) has lost his bid to become a Fine Gael TD.
John Bryan had been widely expected to win the nomination to stand in the by-election in Carlow-Kilkenny, but was defeated last night by councillor David Fitzgerald.
The result is a blow to the party leadership, who were privately backing Mr Bryan.
He had also been expected to run in the European elections last year.
While Willie Quinn was the only Labour candidate in the running for the upcoming by-election, and was officially selected as the candidate last Sunday.
They will join the race with Green councillor Malcolm Noonan, Sinn Féin councillor Kathleen Funchion, Independent councillor Breda Gardner, the Anti-Austerity Alliance's Conor MacLiam and the People Before Profit candidate, Adrienne Wallace.
The vote in Carlow-Kilkenny, to fill the seat left vacant by EU commissioner Phil Hogan, takes place in 11 weeks.