2016 was a challenging year for Podemos. Since its historic success in December 2015’s general election the party has had to deal with growing internal tensions, with leader Pablo Iglesias and his deputy Íñigo Errejón clashing over the party’s future direction.

For months these differences have played out in the national media but this weekend they will take party-political form at Podemos’s second national congress. The stakes are high: members will not only vote for a new national executive but also between competing strategy documents and on a new organizational model. Adding to this is Iglesias’s promise to resign as leader if his electoral list loses.

At the core of this dispute between the Pablistas and Errejonistas is the question of how Podemos, a party that traces its origins back to the indignados movement, should approach its new role as a force in the country’s political institutions. The divisions are particularly pointed on the subject of relations with the center-left Socialist Party (PSOE).