The Socialist Left Party of Norway ( or SV) was founded in 1975. Its history shows a long-term rise in political influence, resulting in part from its emergence from older left-wing parties, especially the Socialist People's Party. After initial political setbacks in the 1970s, the party reorganized and regained support, particularly under Theo Koritzinsky (1983–87) and Erik Solheim (1987–97). Support dropped in the 1997 parliamentary election but rose again by the 21st Century, thanks to the party's position as the only sizeable party to the left of the Norwegian Labour Party. Labour's move further to the right under Jens Stoltenberg also helped the party's rise. By 2005, the Socialist Left Party had joined the Labour and Centre parties in Norway's governing Red-Green Coalition. The party has been led by Kirsti Bergstø since 18 March 2023.

Formation and early years (1973–76)

Socialist Electoral League (1973–75) Year Vote % Type 1973 11.2% Parliament After losing all of its seats in the 1969 parliamentary election, the Socialist People's Party sought to create a coalition of various left-wing parties. Although previously sceptical about working with the Communist Party, it became a member of the coalition, along with the Democratic Socialists – AIK and various independent socialists. Reidar T. Larsen, then leader of the Communist Party, said that members at the party's national convention voted unanimously in favour of joining the coalition, which would later go by the name of the Socialist Electoral League.

The four leading members of the coalition were Finn Gustavsen, Berge Furre (both from the Socialist People's Party), Berit Ås (from AIK) and Larsen (from the Communist Party). Furre and Ås emphasized that the three parties were still operating independently in 1973, while Larsen was very pleased with the outcome, saying that the main object of the Communist Party was to "unite all socialist parties" in one joint cause. The coalition also stressed that they did not want to create a joint platform for the three parties, claiming it to be unimportant for their image. A meeting in September elected Gustavsen as parliamentary leader of the coalition, Roald Halvorsen from the Communist Party as general secretary, and Larsen and Ås to the group board. It was decided that Torild Skard would seek the position of President of the Storting. After the meeting, the party sought to build a closer relationship with the Labour Party and said they would support a Labour-run minority government.

Communist Party and founding (1975) By late 1975, most Communist Party members were against dissolving the party to join what would become the Socialist Left. Reidar T. Larsen, the party leader at the time, supported dissolving the party, while deputy leader Martin Gunnar Knutsen wanted it to continue. Signs before the election showed that the majority supported Knudsen. The media speculated that a faction led by Larsen would split from the party to join the ranks of the Socialist Left.

In the Oslo chapter of the coalition, the Communist Party wanted Arne Jørgensen, editor-in-chief of the Norwegian newspaper Friheten, to get the top position on the election list for the 1975 local elections. However, most Socialist People's Party members in the Oslo chapter did not want him to top the list, because of his background in Norwegian local politics. Socialist People's Party members stated that they had nothing against nominating Communist Party members, pointing out that they had placed communist Karl Kromann in second place. Jørgensen lost the election for the first spot, instead obtaining 11th place on the list and eventually losing his nomination to Socialist People's Party official Fred Dunhaug. Parliamentary leader Finn Gustavsen officially endorsed Jørgensen's candidacy during the national convention in Trondheim, saying he did not want to "split the coalition", which would wreck his plan to unite the coalition into one political party. In May, the Oslo chapter of the coalition held an oral ballot for the top place on the election list, and Jørgensen received 189 votes against Dunhaug's 192. Because the margin was so small, they decided to hold a written ballot, and Dunhaug received 197 votes to Jørgensen's 196. After this result, twenty-one other communist candidates withdrew from their candidacy. This event damaged the unification process and internal conflict continued.

Another conflict between the Socialist People's Party and the Communist Party was the proposal to merge the two party papers, Friheten and Orientering, into a new one. However, Larsen rejected this offer, preferring the two papers to continue even if the two parties merged. Berit Ås felt that the party leadership had weakened its position, saying that they had "kicked the ball over to the communists". After the Communist Party rejected the offer, Orientering was replaced by Ny Tid.

While it was always clear where Larsen stood in the unification process, ever since he became leader of the Communist Party in 1969, he had been able to maintain a strong following in the party. But his support started to waver when he wanted to put an end to the pro-Soviet line the party had held under the leadership of Emil Løvlien. Larsen had always held a vision of one single united left-wing party to the left of Labour, but this vision was not supported by the communist hardliners. In the aftermath of the Communist Party national convention, Larsen said that his speech was "behind closed doors – and behind closed ears". He suffered a clear defeat at the party conference, and he and his remaining supporters left the Communist Party to join the Socialist Left, newly founded by the Socialist People's Party and the AIK without the Communist Party. Because the policies of the Socialist Left were nearly identical to those of the Socialist People's Party, it has often been seen as the latter's direct successor.

Berit Ås (1975–76) Year Vote % Type 1975 5.5%5.7% MunicipalCounty Berit Ås, a compromise candidate for the party leadership, was elected at the so-called unification congress. During the 1975 local elections she became the party's most influential figure. However, her campaigning and her debating skills were criticised both by the Norwegian press and within her own party. During the election campaign, Ås wanted to become the party's representative at the leader debates, a position held since the 1960s by Finn Gustavsen from the Socialist People's Party. The weekly newspaper Dag og Tid described Ås' performance at the leader debates as "messy".

At the party's first national convention in November 1975, it was decided to maintain "a soft party line" towards the remaining Communist Party members still active in the Socialist Left Party. However, they did urge them to leave the Communist Party. Rune Fredh, who had supported Larsen in the Communist Party, called the situation "insane". He still believed that Larsen and the remaining communists would continue to fight for communism in the Soviet Union and the Eastern Bloc.

After experiencing what many observers called a bad election in 1976, a national convention was held early in 1976. During her short tenure, Ås lost all trust amongst party members. Several leading members were calling for Berge Furre to take over as party chairman. However, early in the nomination process, there were rumours that the party's AIK-Communist wing would establish a united front against former Socialist People's Party members. No factions or party notables supported Ås for reelection. It was decided at the convention that Socialist Left Party members could only be members of one party at the time, which meant that the remaining Communist Party members were forced to choose between the Socialist Left Party and the Communist Party. Larsen and Fredh, the Socialist Left Party Secretary, told delegates at the convention that "from now on, the road the Communist Party is following is its own". Furre was elected as party chairman at this convention, with little or no opposition.

On the election list for the 1977 election, Ås became the party's second candidate in Oslo for a seat in the Storting, having lost first place to Stein Ørnhøi. Because of the party's internal difficulties, its electoral base was greatly weakened in 1977: only one Socialist Left candidate from Oslo, and only two nationwide, won seats in the Storting.

Berge Furre (1976–83)

Early leadership and internal strife (1976–77) Berge Furre, previously known unofficially as the Socialist People's Party's "crown prince", became party chairman after the feud between Ås and Finn Gustavsen over who would represent the party during the 1975 local elections. Gustavsen resigned as parliamentary leader, as early signs indicated that he did not have the full support of the party's Election Committee. The party, which suffered several aftershocks after its founding, was severely disorganized. Verdens Gang speculated that the current leadership would be replaced by a troika consisting of Furre (from the Socialist People's Party) as party chairman, Larsen (from the Communist Party) as parliamentary leader and Ås (from the Democratic Socialists – AIK) as deputy leader.

The establishment of the Socialist Left Party had several destabilising effects, such as weakening the party's voter base. Several opinion polls indicated that many voters were leaving, or thinking of leaving, the party or voting for the Labour Party in the 1977 election. As the power struggle between the left- and right-wing factions worsened, Steinar Stjernø was accused of trying to expel the party's social democratic wing (the right-wing faction). However, Sternjø called the rumours absurd. The reason for the accusation was that Stjernø wanted to create a "new and radical alternative for the Norwegian working class". By the time of the national convention where Ås stepped down as party chairwoman, the party had not succeeded in making itself a viable option for the common voter. Furre told the convention's delegates that the party would be able to win over voters, and take several from the Labour Party, if and when the internal situation stabilised. Another difficulty for the party, according to Furre, was that Odvar Nordli's Cabinet was moving the Labour Party further to the centre. It caused some controversy that two of the newly elected Members of Parliament had been convicted of treason for collaborating with the Nazis during World War II.

Electoral activities (1977–81) Year Vote % Type 1977 4.2% Parliament 1979 4.1%4,4% MunicipalCounty 1981 4.9% Parliament Believing that the Labour Party had moved further to the political centre, Furre commented that the Socialist Left Party could only support a left-oriented minority government. Labour Party Secretary Ivar Leveraas responded negatively to Furre's comment, saying "It isn't appropriate for the Labour Party to sit down together with the Socialist Left to discuss our political program and conditions for support, as Berge Furre requires."

Late in 1977, it was known that both Furre and Finn Gustavsen had revealed classified information during an open meeting in the People's House of Oslo on 22 August 1977, after threatening to do so. When this became known, the parliament established a Committee to investigate them. Not knowing what to do, representatives from the Odelstinget voted to shelve the case. There were 44 for and 47 against prosecuting them. When the result was made official, the media speculated that it was some kind of "punishment" of the party, since the incident proved that the party was unable to protect valuable information which could have jeopardized Norway's security interests.