Catalonia’s parliament will defy a Spanish court ban and go ahead with a debate that could lead to a declaration of independence, a regional government official said, as Spain’s worst political crisis in decades looked set to deepen. Secessionist Catalan politicians have pledged to unilaterally declare independence at Monday’s session after staging an independence referendum last Sunday. Madrid had banned the vote and sought to thwart it by sending in riot police who use batons and rubber bullets on voters.