The Social Democratic and Labour Party (SDLP; Irish: Páirtí Sóisialta Daonlathach an Lucht Oibre) is a social-democratic political party in Northern Ireland.The SDLP has fraternal links with other European social-democratic parties including the Irish Labour Party and British Labour Party (neither of which contest elections in Northern Ireland) and is affiliated to the Socialist International and Party of European Socialists. The SDLP is also an Irish nationalist party.