MADRID/BARCELONA - Spain prepared to impose direct rule in Catalonia on Friday, an unprecedented step that risks sparking unrest with secessionists calling on the Catalan parliament to make a defiant declaration of independence.The upper house of Spain's parliament - the Senate - convened at 10 a.m. to consider the government's application of Article 155 of the constitution that allows the central administration to take over a region when it breaks the law.But there was great uncertainty over how this would work on the ground and whether Catalans would accept it. Some independence supporters have promised a campaign of civil disobedience.The crisis has split Catalonia and caused deep resentment around Spain. It has also prompted a flight of business from the wealthy region and alarmed European leaders who fear the crisis could fan separatist sentiment around the continent.The authorization of the Senate, where Prime Minister Mariano Rajoy's People's Party holds an absolute majority, is a necessary step for the government to impose direct rule. A vote in the chamber was expected by 2 p.m. Rajoy was then expected to convene his cabinet to adopt the first measures to govern Catalonia directly. This could include sacking the Barcelona government and assuming direct supervision of Catalan police forces.What could happen in the regional parliament of Catalonia, which was due to meet at noon, was unclear.