The Party of European Socialists (PES) brings together the Socialist, Social Democratic and Labour Parties of the European Union (EU). Its aims include:

• the strengthening of the socialist and social democratic movement in the Union and throughout Europe;
• the development of close working relationships between the national parties, the national parliamentary groups, the Parliamentary Group of the PES, PES Women, ECOSY, and other socialist and social democratic organisations;
• the definition of common policies for the European Union; and
• the adoption of a common manifesto for elections to the European Parliament.