After a pro-independence coalition formed by the Junts pel Sí alliance and the Popular Unity Candidacy won a slim majority in the Parliament in the 2015 regional election, Carles Puigdemont replaced Mas as President of the Generalitat. Puigdemont promised to organise a binding independence referendum based on results from a multi-question, non-binding vote in 2014, when about 80% of those who voted were believed to have backed independence for the region, and up to 91.8% supported Catalonia becoming a state—albeit on an estimated turnout around or below 40%. The Catalan government invoked the right of people to self-determination and Catalonia's political, economical and cultural background to back up its proposal for a referendum on Catalan independence. The Government of Spain, now with Mariano Rajoy as Prime Minister, opposed such a vote, arguing that any referendum on Catalan independence would go against the country's 1978 Constitution, as it made no provision for a vote on self-determination.