Politicisation can be a strategy in which reform advocates use new ideas with coalition magnet attributes to engage a broad range of actors in setting the agenda for policy reform. Comparing the cases of Ecuador and Nepal, the article shows that the generally appealing but ambiguous idea of food sovereignty is a coalition magnet. Through politicisation, agriculture reform advocates in the two countries used the idea to form coalitions of diverse groups supporting reform. But due to the idea’s ambiguities, a coherent set of reform measures is lacking. This has impeded policy reforms in the two countries.