Spain’s top anti-corruption prosecutor has resigned following weeks of pressure that culminated in an admission that he holds a stake in an offshore company in Panama. Manuel Moix stepped down “for personal reasons” on Thursday, shortly after it emerged that he has a quarter-share in a company in the Central American tax haven that was apparently set up as part of an inheritance from his parents. The public prosecutor, José Manuel Maza, told reporters that Moix had resigned even though there was no suggestion “of any irregular or illegal behaviour” on his part. However, Moix’s brief tenure has been dogged by controversy over his alleged attempts to interfere in corruption investigations involving the governing People’s party (PP). The Spanish socialist party (PSOE), which had argued that Moix’s business affairs in Panama made him unfit to pursue corruption, said his resignation had come too late. The PSOE’s newly re-elected leader, Pedro Sánchez, said Moix had been forced out “by media pressure and public opinion”, adding that the decisions and actions of prime minister Mariano Rajoy, who leads the PP, were “seriously damaging the health of our democratic system”. Pablo Iglesias, leader of the anti-austerity Podemos party, said “offshore ministers and prosecutors who corrode democracy and are parasites on institutions” needed to be thrown out of office. In April last year, Spain’s industry, energy and tourism minister, José Manuel Soria, resigned after alleged links to offshore dealing emerged in the Panama Papers, the leaked documents created by the Panamanian law firm Mossack Fonseca. He denied all wrongdoing but said he was stepping down to limit damage to the PP. Moix, who was appointed in February, has been accused of trying to hinder an investigation into fraud involving senior PP members in the Madrid region. Despite his insistence that he had done nothing wrong, opposition parties had been vocal in their calls for him to step down. His departure will be a further embarrassment to Rajoy, whose minority government is mired in several high-profile corruption scandals. Next month, the PP leader will become the first acting prime minister to appear in court as a witness since Spain’s return to democracy when he is called to the Gürtel case. The case – which centres on allegations of a kickbacks-for-contracts scheme involving businessmen and several senior PP members – has been billed as the trial of the year. Rajoy, who is not accused of any wrongdoing, will testify in his capacity as PP leader since 2004. Podemos is set to increase the pressure by bringing a no-confidence vote against Rajoy in a fortnight’s time, arguing that the latest slew of corruption allegations has crossed “red lines” and risks jeopardising the rule of law. Although the move has been dismissed as a stunt and is highly unlikely to secure the backing of parliament, Iglesias insists the government must be held to account. “The anti-corruption prosecutor is trying to do the opposite of fighting corruption; he’s trying to stop prosecutors who are fighting corruption from doing their job,” he said last month. “It means that the People’s party is behaving like a parasite when it comes to institutions; it’s not just looting them to get richer, it’s also risking citizens’ safety by trying to ensure that the police, the guardia civil, judges and prosecutors don’t go after people who are corrupt.” Despite lacking a majority, the PP managed to get the long-delayed 2017 budget approved on Wednesday after winning the backing of smaller parties in return for tax benefits and investment pledges. The budget was passed even though Rajoy accidentally pressed the wrong button, thereby voting against his own plan.