The Portuguese Communist Party (PCP or Partido Comunista Português) is a Marxist‑Leninist party founded in 1921 out of the revolutionary trade‑union and anarcho‑syndicalist movement, becoming the Portuguese section of the Comintern in 1923. Banned after the 1926 coup, it went underground and became a central force of resistance to the Estado Novo dictatorship, organizing clandestine unions, anti‑fascist struggle and supporting the colonial liberation movements. After the 1974 Carnation Revolution, the PCP was pivotal in land reform, nationalisations and embedding social rights in the 1976 Constitution, especially in the Alentejo and Setúbal regions where it has long been very strong.

Today the PCP is a smaller but still influential party rooted in the CGTP trade‑union confederation and local government, holding a handful of Assembly seats and one MEP in the Left group. It advocates a “patriotic and left‑wing alternative”: defence of workers’ rights, public services and national sovereignty, strong criticism of EU and NATO constraints, and support for socialist countries and anti‑imperialist causes.

Chega ("Enough") is a Portuguese far-right populist party founded in 2019 by André Ventura. It positions itself as an anti-establishment movement against what it calls a "rotten and corrupt system" of PS-PSD dominance. The party surged from 1.3% in 2019 to 22.8% in May 2025, becoming parliament's second-largest force with 60 seats. ​ Chega's core platform emphasizes strict immigration control—ending automatic CPLP residency, deporting non-independent immigrants, implementing job-market quotas, and requiring five-year social security contributions before benefit access. It advocates radical constitutional reform, including reducing parliament to 100 members, abolishing the prime minister position for a presidential system, and dismantling public healthcare. Law-and-order policies include life imprisonment and chemical castration proposals.

The party is defined by inflammatory anti-Romani rhetoric, with Ventura convicted multiple times for discrimination. Chega maintains international alignments with European far-right figures including Marine Le Pen, Santiago Abascal, and Matteo Salvini. Mainstream Portuguese parties, including Prime Minister Luís Montenegro's government, have imposed a cordon sanitaire, refusing coalition with Chega despite its parliamentary strength.

Socialist Party (PS)

• Leader: José Luís Carneiro (since June 2025)
• Ideology: Center-left, Social democracy, pro-Europeanism

Portugal's other traditional major party suffered a historic collapse in the 2025 election, dropping from 78 to 58 seats and falling to third place for the first time in democratic history. The party was led by Pedro Nuno Santos from January 2024 until his resignation following the May 2025 defeat. José Luís Carneiro, a 53-year-old former Minister of Internal Administration known for his moderate positioning within the party, was elected unopposed as the new Secretary-General with 95% of votes in June 2025. ​ The Socialist Party governed Portugal from 2015 to 2024, including an absolute majority from 2022 to 2024 under António Costa, who resigned in November 2023 amid a corruption investigation. The PS previously led the innovative "Geringonça" (contraption) coalition government from 2015-2019, a minority government supported by the Left Bloc and Portuguese Communist Party that reversed austerity measures and presided over economic recovery.