At least 40,000 people gathered in Madrid on Sunday to protest over a possible amnesty for people who took part in a failed push for Catalan independence six years ago, whichthrew Spain into its worst political crisis in decades. The divisive issue of an amnesty arose after July’s inconclusive general election. The conservative People’s party (PP) finished first, defeating the governing Spanish Socialist Workers’ party (PSOE) but falling well short of an overall majority. Despite its victory, the PP, led by Alberto Núñez Feijóo, has little chance of securing the necessary parliamentary support to form a new government during a congressional vote this week. The numbers instead favour the PSOE, led by the acting prime minister, Pedro Sánchez. But to stand any chance of forming a new administration, Sánchez will have to secure the backing of the hardline Catalan independence party led by the former Catalan regional president Carles Puigdemont. Puigdemont fled Spain six years ago to avoid arrest over his role in masterminding the unilateral and unlawful push for independence. Puigdemont has insisted his support will be conditional on the granting of amnesty to him and hundreds of other Catalans wanted by Spanish court for their involvement in the attempt at secession. Sánchez – who two years ago pardoned nine Catalan independence leaders convicted over the secessionist push – has refused to rule anything out. But the PP has seized on the possibility of an amnesty to rally its supporters and portray the PSOE leader as cowardly, beholden to Catalan separatists and hellbent on remaining in office. The PP, which organised Sunday’s rally, put attendance at 60,000, while the central government’s delegation to Madrid said it attracted 40,000 people. In his address to the crowd, Feijóo accused Sánchez of “an utter lack of moral and political integrity” and of degrading Spanish democracy. Feijóo said: “The left sees pardons as coexistence, an amnesty as a normalisation and losing as winning. Don’t call us Spaniards stupid because we’re not.” If voters were forced to return to the polls for a repeat election early next year, he said, Sánchez would bear responsibility. In a reference to this week’s congressional vote, Feijóo said: ‘I’m going to defend that Spain is a democracy of free and equal people even if the cost is not being prime minister” He added: “I’ll either be prime minister or I won’t, but what will remain is a free, equal and dignified Spain. Long live Spain.” Sánchez, who criticised the PP earlier this week for what he termed its “apocalyptic prophecies”, has been careful to avoid any explicit mention of an amnesty. Speaking in Catalonia on Sunday, the acting prime minister stressed his commitment to equality, adding that all the social, economic and environmental progress his administration had made would be threatened by a PP government that would have to rely on the support of the far-right Vox party to rule Spain. The PP, which once repudiated Vox for being “a party of fear, of rage, of resentment and revenge”, has rowed back on its objections and formed a number of municipal and regional coalitions with the party over recent years. Sánchez said on Sunday: “If there’s an equality that’s fracturing, that’s in danger, it’s the equality between men and women that’s in peril because of the deals between the PP and Vox.”