Fianna Fáil TD for Dublin North, GV Wright, has announced he will not contest the next General Election.
In a statement, Deputy Wright said he believed it was time for a younger person to take on the role, and that he wished to effect a change in career at a time when he felt capable of taking on new challenges.
He is the second sitting TD in the constituency, after Labour's Sean Ryan, to announce he will be standing down at the end of the current Dáil.
The other sitting TDs are Jim Glennon of Fianna Fáil and Green Party leader Trevor Sargent.
Deputy Wright said he had every confidence that his work will be continued by Deputy Jim Glennon and Councillors Michael Kennedy and Darragh O'Brien.
Deputy Wright was a TD from 1987 to 1989, and from 1997 to date, and was a Senator from 1982 to 1987, and from 1989 to 1997, being Fianna Fáil leader in the Upper House from 1992 to 1997.
He was a member of Dublin County Council, and later Fingal County Council, from 1985 to 2004.
At the Mahon Tribunal, lobbyist Frank Dunlop has claimed he made a payment of £7,000 to Mr Wright when he was a member of Dublin County Council.
He is a former Dublin Gaelic footballer and a former international basketball player and coach.
He was involved in controversy two years ago after a road collision in which a woman pedestrian was injured.
Deputy Wright was fined €900 and banned from driving for two years for drink driving following the incident on the North Strand in Dublin on 18 September 2003.
He had publicly admitted knocking down the woman pedestrian in the incident, which happened while he was on his way home from Leinster House.
The Taoiseach, Bertie Ahern, has paid tribute to Deputy Wright.
In a statement, Mr Ahern said he was 'a hard-working, competent and popular public representative, whose enthusiasm, experience and good humour would be missed by the Fianna Fáil parliamentary party.'