By that time, Portugal was living an unstable political moment: instability, violence and great social tensions were evident after the Carnation Revolution held on 25 April of the same year.

[15] After 25 March 1975, a regime centred in social matters, state control of the economy and military leadership began its efforts to dominate the nation, which summed up with the COPCON (a post-revolutionary military organisation founded in 1974) and the constant attacks perpetrated on the western social democrat model, led the CDS to declare itself officially as an opposition party.

The proposal brought about the creation of the Democratic Alliance (AD), headed by Francisco Sá Carneiro, which won the general elections of 1979 and 1980.

On the night of 4 December 1980, Sá Carneiro and his Minister of National Defence, Adelino Amaro da Costa, were among those who died in a plane crash.

Freitas do Amaral returned as party president, during a period characterised by the electoral success of the PSD, Aníbal Cavaco Silva, to lead a rump of four deputies (later five) in parliament.

In 1993, the CDS-PP was expelled from the European People's Party (EPP), both for rejecting the Maastricht Treaty and therefore being not pro-integrationist enough and for not paying due membership fees.

However, following poor electoral results in local elections in 1997, Manuel Monteiro resigned and was replaced at the party's Braga congress by Paulo Portas who defeated Maria José Nogueira Pinto.

Portas proposed a return to the party's Christian democratic roots and set himself the challenge of keeping all 15 seats in parliament in the general election of 1999.

The CDS-PP contested the 2004 European election in a joint electoral list with the PSD called Forward Portugal (FP), retaining its 2 MEPs.

Due to low popularity and what was seen as the inept handling of the country by the new prime minister, parliament was dissolved after just four months on 30 November 2004 and a new general election was scheduled for February 2005.

The CDS-PP returned to opposition, with its coalition partner the PSD losing to the centre-left PS, whose leader José Sócrates became prime minister.

In the 2009 legislative election, the party increased their share of the votes to 10.4% and won 21 seats, while remaining in opposition to Prime Minister José Sócrates.

Socialist lead António Costa was sworn in as prime minister on 26 November in a minority government, thrusting PàF into opposition.

In March 2016, Assunção Cristas, Portas's chosen successor, was overwhelmingly elected leader of the party over Miguel Mattos Chaves.

The CDS-PP lost 13 of their previous 18 seats, leaving them with only five, and took less than 5% of the vote as António Costa's Socialist government strengthened their position, but fell short of an absolute majority.

A snap election was called for January 2022 after Costa's budget was rejected when the Left Bloc and Communists joined the right-wing parties in voting against it.

The party was led by Francisco Rodrigues dos Santos, the leader of People's Youth, who narrowly won the 2020 leadership election.

The election resulted in a surprise majority for Costa's Socialists after tightening polls, and the CDS-PP lost their five remaining seats on just 1.6% and for the first time since the restoration of democracy returned no members of the Assembly.

The CDS-PP's disastrous results were blamed partially on the rise of other right-wing parties, Liberal Initiative and Chega!, which both saw huge increases in support.

[13] In November 2023, Prime Minister António Costa tendered his resignation after a series of police raids regarding an investigation around alleged corruption involving the award of contracts for lithium and hydrogen businesses,[18] and, shortly after, a snap election was called for 10 March 2024.

In 1995, the party –under the more Eurosceptic leadership of Manuel Monteiro– was kicked out of the EPP; it left the EUCD and joined the Union for Europe group in the European Parliament.