Nov 4 (Reuters) - Portugal will hold a snap general election on Jan. 30 read more Following are snapshots of the main parties and leaders contesting the vote: SOCIALIST PARTY (PS) The centre-left party of Prime Minister Antonio Costa is one of two main parties that have dominated Portugal"s political landscape since 1974"s "Carnation revolution" that ended decades of Antonio Salazar"s dictatorship. It has been in government longest since then. Costa, 60 and a former mayor of Lisbon, has led two consecutive minority governments since 2015, when the Socialists, with support from the hard left, unseated a centre-right coalition government, which presided over four years of tough austerity under an international bailout. His pioneering pact with the Communists and Left Bloc for support in parliament ended in 2019, ultimately leading to the rejection of the 2022 budget bill last week, which triggered the snap election. Under Costa, Portugal achieved solid economic growth and the first budget surplus under democracy in 2019, winning praise from its European partners. The hard left argued he is too focused on spending controls. The PS has 108 seats in the 230-seat parliament after winning 36% of the vote in 2019. Opinion polls show it at similar levels of support. SOCIAL DEMOCRATIC PARTY (PSD) The centre-right party has been the Socialists" main rival for decades. Its leader Rui Rio, 64 and former mayor of Porto, faces an internal leadership vote next month that could see him out, with rival Paulo Rangel widely expected to succeed him. Rangel has criticised Rio for his non-confrontational stance with the Socialists that he says has weakened the opposition. He has ruled out any alliance with the Socialists. The PSD has 79 seats and is polling at around 27%. LEFT BLOC The bloc reached the peak of its popularity on a wave of anti-austerity protests, winning 19 seats in 2015. Aside from its many legislative proposals defending salaries, pensions and the welfare state, it has championed civil rights. Catarina Martins, a 48-year-old actress-turned-politician, has struck a chord in Portugal"s male-dominated politics by mixing an often tough message with a soft delivery. Its support has waned of late and opinion polls show it would lose some seats, unless the break up with the government over the budget gives it a boost. CHEGA ("Enough") Vying for the title of the third-largest force in parliament is the populist, right-wing Chega. Formed in 2019, it won one parliament seat the same year - the first for a far-right party since the end of the dictatorship, and could win over a dozen now. It owes much of its growing popularity to its tough-talking leader, former sports commentator Andre Ventura, 38. Often borrowing populist rhetoric from former U.S. President Donald Trump"s book and encouraged by the fast rise of similarly-minded anti-immigraton, anti-feminist Vox in neighbouring Spain, political analysts see Chega as too toxic a potential partner for any other party in Portugal. COMMUNIST PARTY Led by former metalworker Jeronimo de Sousa, 74, who has honed his skills attacking capitalism for almost five decades in parliament, the party moderated its stance after the pact with Costa, ditching calls to leave the euro zone. After shedding support for years, the party could radicalise its message to try and win back voters. It has 10 seats on its own, plus two in alliance with the Greens. CDS-PP The conservative CDS-PP is PSD"s traditional ally, but has been bleeding voter support to new rivals Chega and Liberal Initiative (IL) and risks losing most of its five seats. The IL, now with one seat, could take as many as CDS-PP"s current representation. PAN (PEOPLE, ANIMALS, NATURE) The environmentalist animal rights party PAN has sided with the Socialists on various occasions and is seen as a potential kingmaker and coalition partner, be it to the centre-left or centre-right. It won four seats in 2019 and could win a few more in this election.