The FMP started publishing the weekly Bandeira Vermelha (Red Flag) which became a popular newspaper among the Portuguese working classes.
The congress was attended by about a hundred members of the party and asserted its solidarity with Socialism in the Soviet Union and the need for a strong struggle for similar policies in Portugal.
Adapting the party to its new illegal status, the re-organization created a net of clandestine cells to avoid a wave of detentions.
[8] Despite the growing repression against the communists, that included the obligation of all civil servant to sign an anticommunist statement,[citation needed] the party still managed to influence riots and demonstrations.
[citation needed] There, on January 18, the workers, led by José Gregório, António Guerra and other Party members, controlled the entire town and only a massive intervention by the military would end the riot.
The vast wave of arrests in the previous years led to the announcement of the definitive end of the PCP by the government, which, along with a growing confidence in the German victory in World War II, led to the liberation of several communist prisoners from Tarrafal and other prisons in November 1940,[10] among them, Álvaro Cunhal, Militão Ribeiro and Júlio Fogaça.
The release of important cadres, combined with the internal dissatisfaction about the decline of the party influenced a major re-organization in 1940–41, named the Reorganization of 40.
In 1944, the Portuguese support of the German war effort created severe shortages of food and goods, greatly decreasing Portugal's living standards.
[8] In 1945, with a whole new international community created by the defeat of the major fascist regimes in World War II, Salazar was forced to make some superficial democratic changes in order to raise Portugal's image in the eyes of its western allies.
[citation needed] A brief report of the conclusions of this congress was published by the Central Committee of the Communist Party of the Soviet Union (CPSU).
[citation needed] At this time, Álvaro Cunhal travelled to Yugoslavia with the aid of Bento de Jesus Caraça in order to improve the relations with the Socialist Bloc.
Later, in 1948, he travelled to Soviet Union in order to speak with Mikhail Suslov, after the ties between the PCP and the International Communist Movement were re-established.
[18] In 1954, a harvest-worker named Catarina Eufémia was murdered by a lieutenant of the Guarda Nacional Republicana after attempting to ask her supervisor for a pay raise.
In January 1960, a remarkable event in the party's history occurred: A group of ten PCP members managed to escape from the high-security prison in Peniche.
Among the escapees was also Jaime Serra, who would help to organize a secret commando group, the Armed Revolutionary Action (Portuguese: Acção Revolucionária Armada or ARA.)
[citation needed] By this time, the Sino-Soviet split and the criticisms of Maoism made during the congress caused the Maoist members to leave the party.
[citation needed] In 1970, the Armed Revolutionary Action made its first attack, sabotaging the Cunene, a ship used to transport supplies for the troops in Africa.
Following several years of turmoil, due to the prolonged war and by the growing unrest caused by the lack of liberties, the regime fell.
On 25 April 1974, the Carnation Revolution occurred, putting an end to 48 years of resistance and marking the beginning of a new cycle in the party's life.
A major struggle of the party was assuring the unity of all labour unions inside the General Confederation of the Portuguese Workers, which was opposed by the Socialists and the Social Democrats.
[27] This resulted in a turn of the revolutionary process to the political left, with the main sectors of the economy, such as the banks, transportation, steel mills, mines and communications companies, being nationalized.
This was done under the lead of Vasco Gonçalves, a member of the military wing who supported the party and who had become prime minister of Portugal after the first provisional government resigned.
In the summer of 1975 the revolutionary process reached its climax, and the government of Vasco Gonçalves, influenced by the left, was under attack from the Socialist Party and the right-wing.
In the aftermath, the party was attacked by the remaining forces, but a notable speech by Melo Antunes, a member of the Group of 9, asserted the importance of the PCP inside the Portuguese democratic regime.
The congress mainly stated the need to continue the quest for Socialism in Portugal and the need to defend the achievements of the Revolution against what the party considered to be a political step backward, led by a coalition of the Socialist Party and the right-wing Centro Democrático Social, who were opposed to the Agrarian Reform process.
The election was won by a right-wing coalition, led by Francisco Sá Carneiro, which immediately started a policy that the party considered to be contrary to working-class interests.
After the sudden death of Sá Carneiro in an airplane crash in 1980, the political instability returned and the right-wing coalition government disintegrated in 1983.
[19] In 1985, a new election was called, prompted by the unstable balance of forces inside the grand coalition and Aníbal Cavaco Silva led the Social Democrats to a narrow victory, the party initiated its electoral decline, gathering only 15.5% of the voting.
The congress analyzed the evolution of the political situation in Eastern Europe and also the right wing policies carried out by the government of Aníbal Cavaco Silva.
[31] The program, which is still the party's program (as of 2006), traced five major objectives to the party's struggle: a free democratic regime, based on the citizens' participation, an economic development based on a mixed economy at the service of the people, a social policy capable of assuring the rise of the country's living standards, culture available to everyone, and an independent and sovereign Portugal, pursuing peaceful relations with all countries and peoples.