Colm Keaveney joins a long and distinguished list of those who have defected to another party.
Noel Browne: Went from Clann na Poblachta to Independent to Fianna Fail to National Progressive Democrats to Labour Party to Socialist Labour to Independent. But he never got into Cabinet again after his controversial time as Health Minister.
Patrick Norton: The son of former Labour Party leader William Norton left the party to join Fianna Fail because he didn't agree with their policies.
Donogh O'Malley: Dropped his membership of Fine Gael to join Fianna Fail and made his place in history by introducing free second-level education.
The PDs: Des O'Malley, Bobby Molloy, Mary Harney, Pat Cox (from Fianna Fail); Michael Keating, Michael McDowell (from Fine Gael) and more: came together under the PDs banner to advance fiscally responsible economic policies.
Martin Cullen: Went in the opposite direction to many PD colleagues to join Fianna Fail and became a Cabinet minister.
Democratic Left to Labour Party: Not quite a defection as the entire party merged and went on to produce its next two leaders, Pat Rabbitte and Eamon Gilmore.
Joe Higgins: Expelled from Labour Party over the Militant Labour issue, he went on to become one of the founders of the Socialist Party.
Mary-Lou McDonald: A member of Fianna Fail in her younger days, she joined Sinn Fein and is now favourite to replace Gerry Adams as party leader.
Pat Cox: Fianna Fail to PDs to Independent from Fine Gael: Joined Fine Gael to try to become their Presidential election candidate, but failed to get the nomination.
Internationally, there have been some exceptional cases: