Mexico\'s lower house of congress passed a bill Saturday that would revamp four-decade-old labor laws, after a raucous debate over reform aimed at making it easier to hire and fire workers. The legislation proposed by conservative President Felipe Calderon was hotly contested by labor unions and leftist parties, whose lawmakers shouted \"no to the reform!\" and even took over the speaker\'s dais during the debate. The bill is also backed by Calderon\'s successor, president-elect Enrique Pena Nieto of the Institutional Revolutionary Party (PRI), who takes office on December 1. Mexico\'s current and next president want to breathe new life into the economy by giving more flexibility to the labor market. Labor rules have not changed since 1970. The bill\'s general outline was approved on Friday in a 351-130 vote after the house speaker, Jesus Murillo Karam, took the unusual step of presiding over the vote from a balcony when leftist lawmakers occupied his dais. The legislators then passed the most contested parts of the reform one-by-one with a large majority, finishing the 14-hour session at dawn Saturday. The bill was backed by the PRI and Calderon\'s National Action Party, or PAN. The bill must now be taken up by the senate within 30 days. Hourly wages, a three-month probationary period for new hires and outsourcing regulation all fall under the reform. But the legislation was toned down to remove articles that would have imposed audits on union finances as well as direct and secret votes for union leaders. The PRI opposed the new union rules.