Opposition against austerity was the cornerstone of the protests which took place since 2010. In Portugal, the first signs of mobilization came from the trade unions, although the emergence of new actors allowed the movementto widen its social influence. This article reflects on the Portuguese contribution to the transnational general strike on the 14 November 2012 in order to explore its insertion in this period’s contentious politics, not only regarding its transnational dimension – within the European Union framework –, but also concerning the relationship between different actors – particularly between trade unions and new political actors. While facing a political agenda aimed at implementing major changes to the regime of labour and social policies, the unions encountered increased challenges regarding the use of their ultimate instrument of struggle – strikes –, especially with consideration to its bases of power, which were already quite weakened ahead of this cycle of mobilization.