According to Mudde (2004), in last decades European democracies are witnessing a populist Zeitgeist. In this sense, populism could be considered contagious and not only exclusive of the alleged populist parties but also present to some extent in mainstream parties. However, other studies (Rooduijn, De Lange and Van der Brug, 2014) have concluded that the programmes of mainstream parties have not become more populists in recent years. In this study, we assess the possible programmatic contagion of Spanish Socialist Workers' Party (PSOE) by Podemos since it has been the mainstream party more affected by the irruption of this new party. In order to reach the aims of the research, a content analysis has been carried out in seven national and European electoral manifestos of PSOE and in three electoral manifestos of Podemos. The period under study (2004-2016) allow us covering different political scenarios in order to control two variables that could affect the PSOE's discourse besides the irruption of Podemos: the position of PSOE as government party (2008, 2009, 2011) or as opposition party (2004, 2014, 2015, 2016), as well as the context of high discontent towards democracy and political parties (2016, 2015, 2014, and less in 2011). The analysis will differentiate two sections: the first section will show the differences and similarities between the electoral manifestos of Podemos and PSOE in quantitative and qualitative terms; and the second, will display the evolution of the electoral manifestos of PSOE since 2004 to 2016. Preliminary results suggest that the electoral manifestos of PSOE cannot be categorised as populists since the party does not try to radicalise the popular sovereignty (one of the core and necessary elements of populism following the ideational definition), although they do content a considerable anti-elitist appeals. Thereby, PSOE’s electoral manifestos identify the existence of some economic and political powers that interfere in the performance of democratic institutions, putting their interests above from those of the people. Regarding their timeline evolution, we identify more anti-elitist appeals in the electoral manifestos when they are in opposition (2016, 2015, 2014 and 2004) than when they are in office (2008, 2009 and 2011), especially in the last three electoral manifestos (2016, 2015 and 2014). The two last electoral manifestos were elaborated in the context of high competition with Podemos, but not the European electoral manifesto of 2014, when Podemos was founded just four months before and had very low electoral expectations. These preliminary results could suggest that it is the combination of the role of opposition and the context of high dissatisfaction with democracy and political parties (2016, 2015, 2014) a prominent factor to explain the increase of anti-elitism in PSOE rather than the competition with Podemos (2016, 2015).