Spanish authorities say two fugitive Catalan separatists elected to the European Parliament must risk arrest by returning to Spain to pick up their official credentials if they want to be European lawmakers.

Spain's Electoral Board ruled Thursday that all the elected candidates from Spain to the European Parliament must come to the Spanish Parliament at noon Monday to swear loyalty to the Spanish Constitution as dictated by election law. If not, their parliament seats will be declared vacant.

Former Catalan President Carles Puigdemont and cohort Toni Comín are wanted in Spain after fleeing the country for Belgium following a failed 2017 attempt by the northeastern region of Catalonia to secede from Spain.

They, along with fellow separatist Oriol Junqueras who is in jail in Madrid, were elected to posts in the May 26 European vote.