[3] Socialistisk Folkeparti (SF) was founded on 15 February 1959 by Aksel Larsen, a former leader of the Communist Party of Denmark (DKP), who was removed for criticizing the Soviet intervention in the Hungarian Revolution of 1956.

SF became involved in peace, anti-nuclear, and grassroots movements, advocating for independence from the Soviet Union.

Throughout the 1960s and 1970s, SF experienced fluctuating electoral success, gaining significant influence in the peace and environmental movements.

Under Gert Petersen's leadership from 1974, SF broadened its appeal, focusing on environmental and gender politics.

The party opposed Denmark's entry into the European Economic Community in the 1972 referendum, which boosted its membership and support.

In the 1980s, SF reached its peak with 27 seats in the Folketing, but faced internal conflicts over EU policies, resulting in fluctuating support.

In the 1990s and 2000s, SF continued to influence Danish politics, supporting the Poul Nyrup Rasmussen government from 1993 to 2001.

Under Holger Nielsen's leadership, SF opposed the 1992 Danish Maastricht Treaty referendum, but supported the Edinburgh Agreement.

Villy Søvndal became party chair in 2005, shifting SF further left and emphasizing professionalism, focus groups, and media strategies.

SF joined the coalition government led by Helle Thorning-Schmidt in 2011, marking its first participation in the cabinet.

Under Pia Olsen Dyhr's leadership since 2014, SF supported the Mette Frederiksen-led Social Democrat minority government after the 2019 election.

It sought to "walk on two legs", by combining its parliamentary work with involvement in grass roots movements.

Just before the referendum in 1991, the SF's party congress had adopted a new program of action and principles, "Mod Nye Tider (Towards New Times)", which departed from the old anti-EU line.

Between 1993 and 2001, the SF supported a Social Democrat/Social Liberal minority government led by Poul Nyrup Rasmussen.

There were some local bright spots with great support to SF mayors in Vejle, Them, Nakskov, Kalundborg, and Maribo caused by charismatic candidates.

In 2004, the party's sole MEP again decided to sit with The Greens–European Free Alliance group, instead of the European United Left/Nordic Green Left, leading to considerable internal conflict.

When Holger K. Nielsen announced that he would step down as chairman, three candidates for the post came forth: Pia Olsen Dyhr, Meta Fuglsang, and Villy Søvndal.

Right-wing politicians praised Søvndal's statements and rhetoric which caused insecurity in some parts of the party who felt they were being embraced by some of SF's main political opponents on the right wing.

[17] Prior to the election, SF spoke with leader of the Social Democrats Mette Frederiksen and brought a list of policy demands.

These included strong climate action and the abolishment of the cash assistance ceiling, though the latter was abandoned during negotiations.

[18] Ultimately it was decided that the Social Democrats would form a one-party minority government supported by SF and the rest of the red bloc.

However, both before and after the election, Prime Minister Frederiksen instead called for the formation of a unity government with the centre-right Liberal Party as well as the newly formed centrist Moderates.

[19] The formation of this grand coalition would make SF the largest party in the opposition with 15 seats, an increase of one compared to the 2019 election.

To that extent, it seeks to reform the World Trade Organization, as well as environmental protection, and support feminism.

The party is also critical of capitalism, with its principle program (adopted in 2012) arguing that "Danish society is characterized by a capitalist structure.

The party was highly Eurosceptic during the 1990s, when SF was the main architect of the four Danish "opt-outs" of the European Union.

The linked Socialist Popular Education Organisation organizes a yearly political summer meeting for members and non-members in Livø.

After 2004 election, SF's sole MEP, Margrete Auken, controversially chose to sit in The Greens-European Free Alliance group.

Without the approval of the party's board, she joined The Greens–European Free Alliance parliamentary group, instead of the European United Left/Nordic Green Left in 2004.

In the 2009 European elections, the party increased its share of votes to 15,6%, and got an additional seat which went to Emilie Turunen, who became a member of the Social Democrats in March 2013.