[1] They opposed the leadership of the SDAP, who were more oriented towards more a revisionist ideology and a parliamentary and reformist political strategy.

[1] Wijnkoop and Ceton refused; they and their supporters, including the poet Herman Gorter and the mathematician Gerrit Mannoury, left to form a new party.

[2] They had a membership of around 400 spread across different cities: Amsterdam (160), Rotterdam (65), The Hague (45), Leiden (56), Utrecht (25), Bussum (15).

The mobilization for World War I, which the SDAP supported and the SDP opposed, further strengthened the differences between the parties.

The Russian Revolution fractured most European parties between their revolutionary and reformist factions; this had already happened in the Netherlands, but it profoundly changed the SDP.

Previously a party of orthodox Marxist intellectuals with little working class support, the SDP saw an influx of members coming from the free socialist organisations, primarily the NAS.

As the German Revolution (and the related Brussels Soldiers' Council) developed across the borders in November 1918, the Netherlands was also affected by strikes and mutinies.

On 10 November, the SDP called for the formation of soldiers' and workers councils with a view to forming a popular government.

The following year, on 10 April 1919 the CPH joined the Comintern,[6] which helped transform the party from a mix of anarchists, syndicalists and orthodox Marxists into a tightly-knit Leninist community.

One of its unsuccessful candidates that year, Tan Malaka, was the first subject of the colonial Dutch East Indies to run for office in the Netherlands.

Jacques de Kadt had already left the party in 1924 to help set up The League of Communist Struggle & Propaganda Clubs.

After the mutiny on the Zeven Provinciën in the same year, the independence of the Dutch Indies became an important theme at the 1933 general election.

Among those elected was the Indonesian nationalist Rustam Effendi, the first subject from the Dutch Indies to enter parliament.

The following period was characterized by decreasing popularity for communism, the rise of internal divisions, and the methodical isolation of the CPN by other parties.

In 1949, a group of Frisian Communists were removed from the party ranks; they founded the Socialist Union, but they were unable to play a significant role in Dutch politics.

In 1958, the Bruggroep ("Bridge group") left the CPN in a conflict over the role of the Communist Eenheidsvakcentrale (Unity Trade Union).

Civil servants were forbidden to become members of the CPN and it was not allowed separate time on public radio or television.

Because of its anti-NATO and European Economic Community stances the party was blocked from the Foreign Affairs, Defense, and Nuclear Energy committees in parliament.

The CPN tried to renew its political program, emphasizing New Left issues like feminism and gay rights.

In 1983 they left the party and formed the League of Communists in the Netherlands (VCN,Verbond van Communisten In Nederland).

The former party chair who was very influential in the formulation of the new liberal course, Herman Meijer, was one of the gay rights activists who joined the CPN in the 1970s.

With the departure of the left-wing grouped around De Internationale, the party adopted Marxism–Leninism, the official ideology of the USSR and the Comintern.

The party remained faithful to the USSR's version of Marxism–Leninism during the 1920s, when Trotsky's interpretation became an important ideological competitor of Joseph Stalin's.

The Communist Party has always been an advocate of the interests of the working class as shown by their advocacy of higher wages and lower prices.

They believed the state should supply cheap housing, free and neutral education and health care insurance.

It favoured Soviet interventions in Czechoslovakia[citation needed] and Hungary and sought Dutch recognition of East Germany.

The support for the SDP, which was founded before the introduction of universal suffrage, was strong among left-wing intellectuals and educated working class circles.

With the introduction of universal suffrage, the SDP, and later CPH began to branch out to the poorest circles of the working classes.

During the Cold War, the PvdA embraced Atlanticism, NATO and the alliance with the United States, while the CPN advocated stronger links with the USSR.

In the 1989 the CPN, PSP and PPR were joined by the left-wing Christian Evangelical People's Party in the formation of the GroenLinks.