Long-standing Labour MEP Proinsias De Rossa has announced he is to step down as a member of the European Parliament from next month.
Mr De Rossa (71), who has served as an MEP for the Dublin constituency since 1999, did not specify his reasons for retiring.
In a statement, he said: "My work as a public representative for 30 years, and before that my 25 years as a grassroots political activist, has always been motivated by a desire to change society for the better."
"I have dedicated all my energies to the pursuit of peace and the elimination of poverty and inequality through peaceful change, and the deepening of democracy."
"These are matters on which I will continue to be active. I hope to participate in efforts to develop and promote alternative policy responses to Europe-wide austerity economics, the deepening of EU democracy and the social market economy, and the recognition of a Palestinian State living in peace alongside Israel," he said.
As a member of the Progressive Alliance of Socialists and Democrats group in the Strasbourg parliament, Mr De Rossa has served on the Employment and Social Policy Committee and currently chairs the European Parliament’s delegation for relations with the Palestinian Legislative Council.
He will be replaced as Labour MEP for Dublin by councillor Emer Costello who is married to Labour TD Joe Costello.
Tánaiste and Labour leader Eamon Gilmore described Mr De Rossa as an inspiration and a great campaigning politician.
"Proinsias has an outstanding record in public life going back 30 years. He has been a great friend and colleague, and on a personal level, was a real inspiration to me when I was first elected as a TD," Mr Gilmore said.
"His reputation among his colleagues and friends, and indeed even among his adversaries in the European Parliament, is that of a passionate, hard-working and dedicated representative of Ireland."
Mr De Rossa first won election to Dáil Éireann in 1982 as a Sinn Féin the Workers Party candidate for the Dublin North West constituency.
He was elected party leader in 1987 and led it to its best ever election result in 1989 when seven TDs were returned.
In the same year, Mr De Rossa was himself elected to both the Dáil and the European Parliament.
He maintained the dual mandate until early 1992 when he stood down as MEP to concentrate on resolving the party’s financial crisis, which ultimately led to his resignation from that party and the formation of the Democratic Left.
Between 1994 and 1997, he served as minster for social welfare in the Rainbow government of the day before securing a seat for a second time in European elections in 1999.
In 1998, Democratic Left and the Labour Party agreed to a merge with Mr De Rossa taking on the role as president of the Labour Party. However he stood down from that post when Pat Rabbitte was elected as Labour Party leader in 2002.
