Síle de Valera is due to step down from her role as Junior Minister for Education today ahead of her retirement from politics at the next election.
The current Clare TD, a granddaughter of Eamon de Valera, was first elected to the Dáil in 1977 in the Dublin mid-county constituency.
She was also elected as an MEP for Dublin in 1979 and was a strong supporter of Charles Haughey throughout her career.
Ms de Valera's decision to vacate her role in government turns the spotlight on the Taoiseach, who is under pressure to appoint backbench TD Sean Haughey to the ministerial ranks.
Bertie Ahern is expected to announce her successor within the next week or so.