The group was mainly based in Catalonia, especially in the city of Barcelona, but also had branches in other parts of the Spanish state, notably in Madrid and Andalusia.

It was also one of the initiators of Aturem la Guerra (Stop the War) platform, which called the huge demonstration in Barcelona on 15 February 2003.

En Lluita/En Lucha was very active in the anti-austerity 15-M movement (2011–15) and participated in the Anticapitalistas’ candidature in the Spanish state-wide elections in 2011 as part of the Des de baix (From below) coalition.

In 2013, a major internal crisis erupted in the British SWP as a result of accusations of rape against a leading member of the party.

In a statement entitled “One step forward, two backwards” the group stated “in the definitive moments of the Catalan independence process, it’s necessary to strengthen the Popular Unity Candidacy (CUP)”.