LISBON Portugal's largest union , the CGTP, has announced a general strike for Dec. 11 to protest a major overhaul of labor laws proposed by the country's center-right minority government. CGTP general secretary Tiago Oliveira, announcing the strike at a Lisbon protest on Nov. 8, described the reform as "one of the greatest attacks ever made against workers" in Portugal. Prime Minister Luis Montenegro says the reforms are aimed at increasing productivity and introducing more flexibility into