Mullagh Councillor Shane P O'Reilly has resigned from Fianna Fáil.
In a statement to Northern Sound News this evening he cited "irreconcilable differences with national party leadership".
He says the party's direction "is not representative of" his aims, beliefs and ideals.
He says he will continue to sit on Cavan County Council as an independent member.
Councillor O'Reilly was first elected to the local authority under the Fianna Fáil banner in 2004.
He twice served as Cathaoirleach of Cavan County Council with his most recent term ending on Monday of this week.
Councillor O'Reilly would not comment further on his resignation when contacted this evening.
Statement from Councillor Shane P O'Reilly
Cllr Shane P O'Reilly wishes to announce after informing the General Secretary and Whip of Fianna Fail that he has resigned from the Fianna Fáil party with immediate effect, Cllr O'Reilly will continue to sit on Cavan Co Council as an Independent member.
Cllr O’Reilly wishes to thank his colleagues on Cavan Co Council for their support and friendship during his 16 years representing Fianna Fáil on the council and wishes them good for the future, unfortunately irreconcilable differences with national party leadership and direction is not representative of Cllr O’Reilly's aims, beliefs and ideals and this has led to this course of action.
Fianna Fáil in Cavan has some of the greatest people in any organisation, but unfortunately for me, I am unable to continue as a representative of Fianna Fail for a raft of personal and national reasons.
