Catalonia’s secessionist leader Carles Puigdemont accused Madrid Thursday of violating the Spanish constitution by threatening to seize the region’s powers to thwart an independence push.

Just a day before Spanish senators were set to pass measures to remove Catalonia’s independence-seeking leadership, Puigdemont insisted in a written submission to the Senate that taking over powers from the semi-autonomous region was an “affront” to Spain’s constitution.