In 1948 following controversy over the
general election, a rebel group called National Liberation Army commanded by
caudillo José Figueres Ferrer led a rebellion against the government of then
President Rafael Angel Calderón Guardia and his
communist allies. After the
Civil War the rebels were victorious and Figueres took power de facto. Yet, Figueres did not overrule the
social reforms made by Calderón and his allies, like
Social Security, almost free college education and Labor Laws, but kept them and even made a series of
progressive reforms himself, like
abolishing the army and introducing taxation on capital. Figueres gave up power in favor of the democratically elected president
Otilio Ulate in 1949. On 12 October 1951, the Social Democratic Party, the Centre for the Study of National Problems and the group Democratic Action formed the National Liberation Party in order to participate in the
1953 election, the first election since the civil war, with Figueres as nominee and
democratic socialism as their ideology. In the
same year's parliamentary election, the PLN won 25 out of 57 seats in the legislature. In the
2010 general election,
Laura Chinchilla, the previous
vice-president and the PLN candidate, won the election with an initial count of 47 percent. A newspaper poll in July 2011 showed a decline in party popularity. Commentary on the poll pointed to an inherited fiscal crisis, border friction with Nicaragua, and natural disasters the previous November as contributing factors to public discontent. In 2013, the PLN's candidate was
Johnny Araya (Rolando Araya’s brother),
San José Mayor since 1982, after other aspirants like former Presidential Minister Rodrigo Arias (Óscar Arias' brother) and former president
José María Figueres (José Figueres' son) dropped from the race due to low polling numbers, making a primary unnecessary. Araya was the frontrunner for a while in most polls but finished second in the first electoral round, earning only 29% of the votes, the lowest percentage ever for a PLN nominee, and behind PAC's nominee
Luis Guillermo Solís. For the run-off election Araya resigned his candidacy arguing that he had no more money to run a campaign and that all polls showed him losing by wide margin. Effectively in the second round Solís won with 78% of the votes and Araya gained only 22%. Araya was expelled from the party after a resolution of the Ethics Committee due to his resignation as candidate in the second round (something unconstitutional, as the
Constitution does not allow resigning a candidacy), thus Araya ran for Mayor of San José with a local party, winning the election in the
2016 municipal elections, in which PLN was the most voted party, yet it lost 14 mayoralties and received much fewer votes that in the previous municipal election. The party, then as main opposition to
Luis Guillermo Solís's government, went into a very divisive
primary in which then deputy
Antonio Álvarez Desanti won over former president
José María Figueres. Internal fighting made impossible to reach an agreement among the factions leading to Figueres withdrawing his support of Desanti's nomination. Desanti, who had previously left the party whilst criticizing it for corruption and abandoning its social-democratic ideology, had the support of
Oscar Arias and his brother Rodrigo, however. Nevertheless its results in the
2018 Costa Rican general election were crushing, as the party suffered its worst defeat in history with only 18.6% of votes and failing to gain a spot in the run-off, ending as third for the first time in its history. It also finished with its worst parliamentary results. The party saw an improvement in the
2022 general election, finishing first in the first round of the presidential election, although losing in the runoff. It finished second in the
2026 election. == Party leadership ==