The Social Democratic and Labour Party or SDLP is a centre-left political party in Northern Ireland. Its policies promote social democracy and the idea that Northern Ireland should leave the United Kingdom and join with the Republic of Ireland. Its leader is Colum Eastwood and currently it has none of the Northern Ireland seats in the UK parliament, however it has 12 out of 90 seats in the Northern Ireland Assembly making it the 3rd largest party in the assembly .