The French Communist Party (French: Parti Communiste Français; abbreviated PCF) has been a part of the political scene in France since 1920, peaking in strength around the end of World War II. It originated when a majority of members resigned from the socialist French Section of the Workers' International (SFIO) party to set up the French Section of the Communist International (SFIC). The SFIO had been divided over support for French participation in World War I and over whether to join the Communist International (Comintern). The new SFIC defined itself as revolutionary and democratic centralist. Ludovic-Oscar Frossard was its first secretary-general, and Ho Chi Minh was also among the founders. Frossard himself resigned in 1923, and the 1920s saw a number of splits within the party over relations with other left-wing parties and over adherence to the Communist International's dictates. The party gained representation in the French parliament in successive elections, but also promoted strike action and opposed colonialism. Pierre Semard, leader from 1924 to 1928, sought party unity and alliances with other parties; but leaders including Maurice Thorez (party leader from 1930 to 1964) imposed a Stalinist line from the late 1920s, leading to loss of membership through splits and expulsions, and reduced electoral success. With the rise of Fascism this policy shifted after 1934, and the PCF supported the Popular Front, which came to power under Léon Blum in 1936. The party helped to secure French support for the Second Spanish Republic during the Spanish Civil War and opposed the 1938 Munich Agreement with Hitler. During this period the PCF adopted a more patriotic image, and favoured an equal but distinct role for women in the communist movement.

The party was banned in 1939 on the outbreak of World War II. Under Comintern direction the PCF opposed the war and may have sabotaged arms production. The leadership, threatened with execution, fled abroad. After the German invasion of 1940 the party failed to persuade the occupiers to legalise its activities, and while denouncing the war as a struggle between imperialists, began to organise opposition to the occupation. When Germany invaded the Soviet Union the next year, the Comintern declared Germany to be an enemy, and the PCF expanded its anti-German activities, forming the National Front movement within the broader Resistance and organising direct action and political assassinations through the armed Francs-Tireurs et Partisans (FTP) group. At the same time the PCF began to work with de Gaulle's "Free France", the London-based government in exile, and later took part in the National Council of the Resistance (CNR).

By the time the German occupation ended in 1944, the party had become a powerful force in many parts of France. It was among the leading parties in elections in 1945 and 1946, and entered into the governing Tripartite alliance with the socialist SFIO and the Christian democratic MRP. The Tripartite governments pursued social reforms and statism. However, amid concerns within France and abroad over the extent of communist influence, the PCF was excluded from government in May 1947. Under pressure from Moscow, the PCF thereafter distanced itself from other parties and focused on agitation within its trade union base. For the rest of the Fourth Republic period the PCF, led by Thorez and Jacques Duclos, remained politically isolated, still taking a Stalinist line, though retaining substantial electoral support.

Although the PCF opposed de Gaulle's formation of the Fifth Republic in 1958, the following years saw a rapprochement with other left-wing forces and an increased strength in parliament. With Waldeck Rochet as its new secretary-general, the party supported François Mitterrand's unsuccessful presidential bid in 1965 and started to move apart to a limited extent from the Soviet Union. During the student riots and strikes of May 68, the party supported the strikes while denouncing the revolutionary student movements. After heavy losses in the ensuing parliamentary elections, the party adopted Georges Marchais as leader and in 1973 entered into a "Common Programme" alliance with Mitterrand's reconstituted Socialist Party (PS). Under the Common Programme, however, the PCF steadily lost ground to the PS, a process that continued after Mitterrand's victory in 1981.

Initially allotted a minor share in Mitterrand's government, the PCF resigned in 1984 as the government turned towards fiscal orthodoxy. Under Marchais the party continued loyal to the Soviet Union up to its fall in 1991, and made little move towards "Eurocommunism". Extensive reform of the party's structure and policies had to wait until 1994, when Robert Hue became leader. The party's renunciation of much traditional communist dogma after this did little to stem its declining popularity, although it entered government again in 1997 as part of the Plural Left coalition. Elections in 2002 gave worse results than ever for the PCF, now led by Marie-George Buffet. Under Buffet, the PCF turned away from parliamentary strategy and sought broader social alliances. It condemned the Nicolas Sarkozy government's response to riots in 2005 and adopted a more militant stance towards the European Union. Buffet's attempt to stand in the 2007 presidential election as a common candidate of the "anti-liberal left" had little success. To maintain a presence in parliament after 2007 the party's few remaining deputies had to group together with those from The Greens and others to create the Democratic and Republican Left group (GDR). Subsequently, a broader electoral coalition, the Left Front (FG), was formed including the PCF, Jean-Luc Mélenchon's Left Party (PG), Unitary Left, and others. The FG has continued up to the present and has brought the French communists somewhat better electoral results, at the price of some tension within the party and with other parties in the FG. With Pierre Laurent as leader since 2010, in a symbolic move the party no longer includes the hammer and sickle logo on its membership cards.

Foundation

The French Communist Party was founded in December 1920 by a split in the socialist French Section of the Workers' International (SFIO), led by the majority of party members who supported membership in the Communist International (or "Comintern") founded in 1919 by Lenin after the Bolshevik Revolution in Russia.

The outbreak of World War I in 1914 sparked tensions within the SFIO, when a majority of the SFIO took what left-wing socialists called a "social-chauvinist" line in support of the French war effort. Gradually, anti-war factions gained in influence in the party and Ludovic-Oscar Frossard was elected general secretary in October 1918. Additionally, the success of the Bolshevik Revolution in Russia aroused hope for a similar communist revolution in France among some SFIO members.

After the war, the issue of membership in the new Communist International became a major issue for the SFIO. In the spring of 1920, Frossard and Marcel Cachin, director of the party newspaper L'Humanité, were commissioned to meet with Bolshevik leaders in Russia. They observed the second congress of the Communist International, during the course of which Vladimir Lenin set out the 21 conditions for membership. When they returned, Frossard and Cachin recommended that the party join the Communist International.

At the SFIO's Tours Congress in December 1920, this opinion was supported by the left-wing faction (Boris Souvarine, Fernand Loriot) and the 'centrist' faction (Ludovic-Oscar Frossard, Marcel Cachin), but opposed by the right-wing faction (Léon Blum). This majority option won three quarters of the votes from party members at the congress. The pro-Comintern majority founded a new party, known as the French Section of the Communist International (Section française de l'Internationale communiste, SFIC), which accepted the strict conditions for membership.

A majority of socialist parliamentarians and local officeholders were opposed to membership, particularly because of the Communist International's strict democratic centralism and its denunciation of parliamentarianism. These members went on to form a rump SFIO, which had a much smaller membership than the SFIC but which could count on a strong base of officeholders and parliamentarians.

The founders of the SFIC took with them the party paper L'Humanité, founded by Jean Jaurès in 1904, which remained tied to the party until the 1990s. In the General Confederation of Labour (CGT) trade unions, the Communist minority split away to form the United General Confederation of Labour (CGTU) in 1922.

The new communist party defined itself as a revolutionary party, which used legal as well as clandestine or illegal means. The party organization was run under strict democratic centralist precepts, until the 1990s: the minority factions were compelled to follow the majority faction, any organized factions or contrary opinions were forbidden, while membership was tightly controlled and dissidents often purged from the party.

Ho Chi Minh, who would create the Việt Minh in 1941 and then declare the independence of Vietnam, was one of its founding members.

Marginalization (1922–1934)

In its early years, as the communists fought the SFIO for control of the French left, the new party was weakened and marginalized by a series of splits and expulsions.

The "bolshevization" or stalinization imposed by the Communist International, as well as Zinoviev's power over the Communist International, led to internal crises. "Bolshevization" implied not only the adoption of the political strategy of the Communist International but a reorganization of party's structure on the model of the Bolsheviks (discipline, local organization under the shape of "cells", ascent of a young political staff which came from the working-class).

The first secretary-general of the PCF, Ludovic-Oscar Frossard, was often reluctant to obey the directives of the Communist International. Indeed, the party leadership was opposed to the strategy of the "proletarian unique front". Furthermore, one of Frossard's internal opponents, Boris Souvarine, was a member of the secretariat of the Communist International. Frossard resigned and left the PCF in 1923 to found a dissident United Communist Party which later became the Communist Socialist Party (but Frossard himself rejoined the SFIO). The general secretariat of the Party was shared by Louis Sellier (center faction) and Albert Treint (left-wing faction). At the same time, Boris Souvarine was expelled from the Communist International and the PCF due to his sympathy for Leon Trotsky.

In the 1924 legislative election, the PCF won 9.8% of the vote and 26 seats, considerably weaker than the SFIO. But under the leadership of the left-wing faction, priority was given to general strikes and revolutionary actions rather than elections. In the French Parliament, the PCF's first elected deputies were opposed to the Cartel des Gauches coalition formed by the SFIO and the Radical Party, which governed between 1924 and 1926.