| Albania |
Social Democratic Party, PSD |
| Albania |
Socialist Party of Albania, SPA |
| Andorra |
Social Democratic Party of Andorra, PS |
| Armenia |
ARF Armenian Socialist Party |
| Austria |
Social Democratic Party of Austria, SPÖ |
| Belgium |
Socialist Party, PS |
| Belgium |
Socialist Party, SPA |
|
Bosnia and Herzegovina
|
|
|
Bosnia and Herzegovina
|
|
| Bulgaria |
Bulgarian Social Democrats, PBSD |
| Bulgaria |
Bulgarian Socialist Party, BSP |
| Croatia |
Social Democratic Party, SDP |
| Cyprus |
Movement of Social Democrats EDEK |
| Czech Republic |
Czech Social Democratic Party, CSSD |
| Denmark |
Social Democratic Party |
| Estonia |
Estonian Social Democratic Party
|
| Finland |
Finnish Social Democratic Party, SDP |
| France |
Socialist Party, PS |
| Germany |
Social Democratic Party of Germany, SPD |
| Great Britain |
The Labour Party |
| Greece |
Panhellenic Socialist Movement, PASOK |
| Hungary |
Hungarian Social Democratic Party, MSzDP |
| Hungary |
Hungarian Socialist Party, MSzP |
| Iceland |
Social Democratic Alliance |
| Ireland |
The Labour Party |
| Italy |
Democrats of the Left, DS |
| Italy |
Socialist Party, PS |
| Latvia |
|
| Lithuania |
Lithuanian Social Democratic Party, LSDP |
| Luxembourg |
Luxembourg Socialist Workers' Party, LSAP/POSL |
|
The Former Yugoslav Republic of Macedonia
|
Social Democratic Union of Macedonia, SDSM |
| Malta |
Malta Labour Party |
| Montenegro |
Social Democratic Party of Montenegro, SDPM |
| Montenegro |
Democratic Party of Socialists of Montenegro, DPS |
| Netherlands |
Labour Party, PvdA |
| Northern Ireland |
Social Democratic and Labour Party, SDLP |
| Norway |
Norwegian Labour Party, DNA |
| Poland |
Democratic Left Alliance, SLD |
| Poland |
Union of Labour, UP |
| Portugal |
Socialist Party, PS |
| Romania |
Social Democratic Party, PSD |
| San Marino |
Party of Socialists and Democrats |
| Serbia |
Democratic Party, DS |
| Serbia |
Social Democratic Party of Serbia |
| Slovakia |
SMER-Social Democracy |
| Slovenia |
Social Democrats, SD |
| Spain |
Spanish Socialist Workers' Party, PSOE |
| Sweden |
Swedish Social Democratic Party, SAP |
| Switzerland |
Social Democratic Party of Switzerland |
| Turkey |
Republican People's Party, CHP |