Brussels, 03/10/2003 (Agence Europe) - The Party of European Socialists (PES) will meet on Tuesday afternoon at the European Parliament in Brussels, for an extraordinary meeting to mark its 50th anniversary. Taking part in debates will be: Jacques Delors, former President of the European Commission, Leszek Miller, Poland's Prime Minister and his Romanian counterpart Adrian Nastase, the PES chairman, the Spaniard Enrique Baron Crespon, Massimo D'Alemo, chairman of Italy's Democratic Partyof the Left, both chairmen of the Belgian socialist party, Elio di Rupo for the French-speaking section, and Steve Stevaert for the Flemish-speaking part, and British MEPs John Hume and Katherine Stihler.