Long-standing Fianna Fáil councillor Kenneth O'Flynn is to run in the General Election as an independent candidate.
Mr O'Flynn made the announcement just hours after Fianna Fáil omitted him from their completed ticket in Cork North-Central.
The former deputy Lord Mayor of Cork had hoped to be added to the ticket alongside TD Padraig O'Sullivan but party leadership opted for Cllr Tony Fitzgerald, a former Lord Mayor, and Sandra Murphy, who has experience in hospitality and events management.
Mr O'Flynn's announcement could cause a headache for the party as he topped the poll in the local election last May and remains popular in the city.
Announcing his decision, he said, "It has always been my intention to seek to represent the people of Cork North Central in Dáil Éireann.
"The Fianna Fáil party leadership has not selected me to run as a candidate. I am of course disappointed having served the party for the last 25 years and as a Councillor for the last 12 years, but it is not about the party, it is about the people of Cork North Central."
He has committed to being an "independent voice in Dáil Éireann."
Mr O'Flynn's office will be managed by his father Noel, who served as a TD for Cork North-Central for 14 years.