Left and Democrats was a centre-left electoral alliance of political parties in Poland which was created on 3 September 2006, before the Warsaw municipal election of 2006. The coalition's aim was to provide an alternative for both Law and Justice and Civic Platform, which have been Poland's two major political parties since 2005. LiD contested their first national election in October, 2007 and won 53 seats to the Polish parliament, the Sejm. The LiD alliance was dissolved in April 2008, following a rift between the member parties.

Parliamentary elections were held in Poland on 21 October 2007, after the Sejm voted for its own dissolution on 7 September. The election took place two years before the maximum tenure of four years, with the previous elections having been in September 2005. The early elections were a result of serious allegations of massive corruption on the part of Andrzej Lepper, leader of the Self-Defense of the Republic of Poland, whose party served as a junior coalition partner to the government of Prime Minister Jarosław Kaczyński. All 460 seats in the Sejm and all 100 seats in the Senate were up for election.