In the government control session held on the 22nd of March the Minister of Economy, Industry and Competitiveness declared that Spain will not join the UPC. The reasons given at the Lower House of the Parliament are difficult to grasp.
The main one seems to be that Spanish is not an official language of the UPC and "the companies would have to translate their patent applications into one of the three official languages and would also have to respect patents which are not translated into Spanish". Of course, this objection would mean that Spain should not be a party to the European Patent Convention where Spanish is not an official language. The Minister's intervention also shows a worrying isolationist attitude. In fact, commentators have spotted the contradiction of the Minister, who has recently imposed on Spanish listed companies the requirement to make communications to the Spanish Security Commission in English and at the same time rejects the UPC for linguistic reasons. The Deputy of the Socialist Party that posed the question, Ms. Blanquer, underlined the significant savings derived from the UPC and the loss of competitiveness for Spanish companies by the Government's rejection.
You can watch the Minister's intervention (in Spanish). It begins at minute 37'.