The party was formed in January 1997 with the merger of some minor Christian-democratic party and a conservative faction of the liberal Freedom Union, the latter led by Jan Rokita. The party soon joined the centre-right Solidarity Electoral Action coalition and was subsequently part of it in the 1997 parliamentary election. The coalition won 33.8% of the vote and 201 seats in the Sejm, 14 of which were SKL members, notably including Rokita and Bronislaw Komorowski.
Within the coalition, the SKL represented the more liberal wing. In the 2000 presidential election Marian Krzaklewski was the coalition's official candidate and won 15.6% of the vote, but a large chunk of the coalition, especially SKL members, had supported the independent candidate Andrzej Olechowski,[2] who won 17.3% of the vote.
In January 2001, when the Solidarity Electoral Action was re-organised as a federation, it was one of the four member parties, the other being the Social Movement, the Christian National Union and the Polish Christian Democratic Agreement. However, in March 2001 the SKL withdrew from the coalition and most of it would later join, indirectly or directly, Civic Platform, which had been established in January 2001. In the 2001 parliamentary election the SKL participated within Civic Platform's electoral slates.
In 2002 what remained of the SKL was merged with the Polish Christian Democratic Agreement, while Rokita was Civic Platform's leader in the Sejm from 2003 to 2005. In 2004 the SKL and the Social Movement were replaced by the Centre Party. The Conservative People's Party was revived in 2007 and lasted until 2014, when it became part of Poland Together.