Pedro Sánchez is preparing for a fraught and turbulent second term as Spain’s prime minister after his socialist party regained power by agreeing to a deeply controversial amnesty for Catalan separatists that has infuriated rightwing parties and led to huge protests across the country. The investiture vote on Thursday came almost four months after an inconclusive snap election in July in which Sánchez’s governing Spanish Socialist Workers party (PSOE), was narrowly defeated by its conservative rivals in the People’s party (PP). Sánchez won an absolute majority in Thursday’s vote, securing the support of 179 of Spain’s 350 MPs after a bad-tempered and bitter debate. Although the PSOE hailed the result as proof that “democracy will always prevail over noise and darkness”, its victory has come at a high price and has depended on the backing of smaller regional parties, including Catalan and Basque nationalists. The PP, despite finishing first in July’s election, proved unable to form a government with the support of the far-right Vox party and other smaller groupings. Sánchez and his partners in the leftwing Sumar alliance, however, managed to cobble together the necessary backing for their coalition by acceding to the amnesty demands of the two main Catalan pro-independence parties – the pragmatic Catalan Republican Left (ERC) and the hardline Junts per Catalunya (Together for Catalonia). A draft law, tabled by the PSOE on Monday, will offer an amnesty to hundreds of people involved in efforts to bring about Catalan independence over the last decade. Sánchez’s manoeuvring – and the fact that he had ruled out such an amnesty during the election campaign – has prompted fury from the PP and Vox, which have accused him of hypocrisy, caving into the separatists and putting self-preservation before the national interest. The PP has called on the EU to weigh in on the proposed law, while Vox has suggested the acting prime minister is perpetrating “a coup d’état in capital letters”. The deeply divisive issue has also led to large demonstrations across Spain and angry and violent clashes between police and fascists and neo-fascists outside the PSOE’s Madrid headquarters. To complicate matters further, Junts has already told Sánchez not to expect its unconditional support over the next four years. Sánchez argues the amnesty will allow Spain to turn the page on the past. “In the name of Spain and its interests and in the defence of coexistence between Spaniards, we’re going to grant an amnesty to those people who are facing legal action over the [Catalan independence] process,” he told MPs on Wednesday, as the investiture debate began. “This amnesty will benefit many people, political leaders whose ideas I do not share and whose actions I reject, but also hundreds of citizens who were swept up in the process.” The move, he added, was not the attack on the Spanish constitution that his opponents had claimed, but rather “a demonstration of its strength”. But the PP’s leader, Alberto Núñez Feijóo, said on Thursday that “the democratic warning lights” were flashing now that Sánchez had yielded to the independence movement. “We’ll try to work for our country and to recover the sanity that the personal ambition of the man who is now prime minister had led down a blind alley,” he said. A day earlier, Feijóo had launched a scathing attack on Sánchez for agreeing to an amnesty that would include Carles Puigdemont, the Junts leader and self-exiled former Catalan president who masterminded the 2017 attempt to secede before fleeing to Belgium to avoid arrest. “You are the problem,” he said. “You and your inability to keep your word, your lack of moral limits, your pathological ambition. As long as you’re around, Spain will be condemned to division. Your time as prime minister will be marked by Puigdemont returning freely to Catalonia. History will have no amnesty for you.” After the vote, Vox called for the PP’s cooperation in fighting what it called Sánchez’s “coup”, adding that the PSOE leader had become a “despot”. Not all the admonishments came from Sánchez’s opponents. Junts, perhaps annoyed by the acting prime minister’s mention of a “united Spain”, advised him “not to tempt fate”, warning that its support for his minority coalition government was conditional and would be offered on a case by case basis. “If we are here today it is to make things really change,” Junts’ spokesperson, Míriam Nogueras, said on Wednesday. “But if there is no progress, we will not approve any initiative presented by your government. It is linked to progress and compliance with agreements.” The draft amnesty bill covers the period from 1 January 2012 to 13 November 2023, so its scope includes the symbolic, consultative independence referendum of November 2014 and the one three years later that was followed by a unilateral declaration of regional independence. Its beneficiaries include 309 people who faced criminal lawsuits and 73 police officers who faced criminal action over their conduct on the days before and after the second referendum. Although the amnesty will allow Puigdemont to return to Spain and some of his former colleagues to have their bans on holding public office lifted, the socialists have sought to emphasise that the act of clemency was more general. They said it was designed to apply to headteachers who faced legal action for allowing their schools to be used as referendum polling stations, and to civil servants, firefighters and police officers. Sánchez also used his speech on Wednesday to announce a series of measures aimed at helping people weather the cost of living crisis. As well as introducing free public transport for young people and unemployed people from next year, he said his government would increase rental subsidies for young people, extend the threshold for mortgage relief support, and reduce the working week from 40 to 37.5 hours by 2025. Despite the dire warnings from the PP and Vox, Sánchez’s return to office was welcomed by his fellow European leaders. The German chancellor, Olaf Scholz, and the European Council president, Charles Michel, were among the first to offer their congratulations.