The S&D Group voices the goals and concerns of European socialists and social-democrats in the European Parliament. However it also works closely with sister organisations outside the EU institutions: the Party of European Socialists and the Foundation for European Progressive Studies.
The S&D Group in the European Parliament is composed of MEPs who belong to national parties which share our social-democratic values and are members of the Party of European Socialists. 
The Party of European Socialists (PES) is politically represented in the European Parliament, in the European Council and Council of Ministers, and in the Committee of the Regions. The European Commission – although an independent, collegiate body – also has several commissioners who are members of PES parties.
The Foundation for European Progressive Studies (FEPS) is an independent thinktank close to the PES. FEPS encourages the exchange of ideas and new ways of thinking on the social-democratic, socialist and labour scene in Europe.