This thesis is concerned with the social mobilisation in Spain provoked by the financial crisis which started in 2008. Specifically, the thesis analyses the intersections of the housing movement with some political coalitions that won many municipalities in 2015. It does so to explain the dynamics that lead to the creation of a “space of activism” capable of opposing the capitalist organisation of space. Since the beginning of the crisis thousands of Spanish people have lost their homes because they were unable to pay their mortgages. The debt that these people have contracted for covering their housing needs has become such an unbearable burden that many see protest as the only way to avoid being thrown onto the streets. The consequent mobilisation has been canalised mainly through the Platform of People Affected by Mortgages (PAH). Created in Barcelona, this organisation has expanded all over the country, not due to a centralised strategy directed from Barcelona, but to a “contagious” shooting up of chapters that provokes a strong independence among the chapters and a focus on local mobilisation. Despite being able to stop evictions and to force the renegotiation of individual mortgages, PAH has failed to force legal or systemic changes. These difficulties animated many activists to promote the creation of multiple coalitions with diverse political organisations to run for the 2015 local elections. In interrogating what the dynamics that shape this mobilisation are and examining the transition between the movements, this thesis focuses on two definitory characteristics of these organisations. The first one is their high degrees of heterogeneity. This heterogeneity became evident in PAH due to the coexistence of different social classes, nationalities, perceptions or values. Whereas in the municipal platforms, the heterogeneity was mainly linked to the coalition of multiple political groups with diverse ideologies. The thesis explores the role and the influence of this heterogeneity, and the way the different groups handle it. The second definitory characteristic is the high levels of decentralisation and localism that mark the activism of these organisations. That said, the groups are not totally disconnected from each other and their localism is accompanied by certain forms of integration that raise questions about how these connections take place and articulate the different local struggles. In reflecting about these definitory characteristics, the thesis investigates the relation between heterogeneity and the production of space, as well as its relation to the development of certain forms of agency. The fieldwork was based on ethnocartographic research in two local chapters of PAH (PAH Barcelona and Stop Desahucios Coruña) and two municipal coalitions (Barcelona en Comú and Marea Atlántica) in order to research groups of different sizes, visibility and in different contexts. Ethnocartographic methods aim to map the affective relations between the activists that shape certain dynamics that influence the way the activism develops. To advance in this direction, the thesis excavates the possibility of combining Deleuze and Guattari’s conceptualisation of politics with that of Lefebvre’s theory concerning the production of space. Grounded in their common interest in relationality, everyday life and heterogeneity, the theoretical framework explores the potential of this combination to analyse the connections between the general dynamics that shape activism and the redefinition of agency so as to contest neoliberal urbanism. The analysis excavates how the contention developed by these local groups produces specific forms of space and the potential of these to become spaces of everyday life that confront capitalist representations which organise space. By focusing on this production of space, the thesis addresses the role of heterogeneity in those dynamics and the changes in the agency of the activists. The research reveals the importance of space as the product of the confrontation between the capitalist attempts to organise space and its resistances by the users. The activism, especially that of PAH, has implemented a change in the affective relationships of those subjected to debt. These people transform their passive subjection to the constraints imposed by a spatial organisation around debt into an active agency that mobilises an affective capability to challenge that indebtedness. The coming together of heterogeneous groups of people and their perceptions proved to be the key for this mobilisation, this is especially so concerning the central role of certain activists that incorporate their antagonist perceptions in those affective relations. Nevertheless, the cases demonstrated how, to challenge indebtedness and capitalist imposition, the heterogeneity has not only to be exposed and articulated, but also assembled. When the different perceptions are assembled new representations emerge. These favour the development of new perceptions that confront individual subjectification. The thesis argues that these new representations of everyday life do not develop a full confrontation of capitalist representations. They need the creation of other spaces to avoid jeopardising the cohesion of heterogeneity. It is in these terms that the coalitions must be understood. These coalitions fully develop the abstraction of demands hinted by the representations developed by PAH, by completing a transition from the performative politics that were predominant in PAH to the representational politics that become dominant in the coalitions. The thesis argues that the way in which this transition is made, by avoiding dynamics of rescaling, has favoured the cohesion of the groups, reduced the tensions linked to dynamics of abstraction and generated a “space of activism” based on horizontality that poses a considerable challenge for capitalism to reimpose subjection.