European Parliament President Pat Cox today bid an emotional farewell to his fellow MEPs as he announced he would not be standing for re-election in the June poll.
His resignation will fuel speculation that he is to become Ireland's next EU Commissioner.
Making his final speech as president in the parliament's last legislative session before the elections, Mr Cox said he had informed his Munster constituents this morning of his decision to stand down after 15 years as a Liberal MEP.
"Serving as an MEP for 15 years and as President for almost two and half years has been the great experience of my life," he told MEPs in Strasbourg.
"Although no business in politics is ever finished, I know others are there to take up the challenge."
Mr Cox received a standing ovation from a packed chamber, which included European Commission President Romano Prodi and UK Commissioner Neil Kinnock.
The Taoiseach, Mr Ahern, thanked Mr Cox for his "outstanding contribution and work". He said it had been a pleasure to work with Mr Cox adding: "I wish Mr Cox well in which ever path he may choose in the future".
Fine Gael MEP, Mrs Avril Doyle, said Mr Cox has represented Ireland in Europe, and on the global stage with "great professionalism and dignity and he can take enormous personal satisfaction from the job he has done."
Labour party leader in the Seanad and European election candidate, Mr Brendan Ryan, said: "Pat Cox's achievements in the parliament show that it is possible for an effective MEP to make a difference".