Two companies that employ independent workers are taking legal actionto block a California law that offers protections to such workers.The ride-sharing company Uber joined delivery service Postmates in the lawsuit.The two companies argue that the new law violates federaland state constitutional guarantees of equal protection and fair justice.The law is set to take effect in California on Wednesday.Supporters have argued that the new rules protect the rights of workers who are independent contractors.The law requires companies to provide some independent contractorswith the same kinds of work protections and benefits that employees receive.In addition to Uber and Postmates, the lawsuit includes two independent workers fighting the law.California Governor Gavin Newsom signed the law in September.It has brought greater attention to the rights of independent workers.The California law is seen as a possible model for future legislation in other states.Companies like Uber, Lyft, Postmates and others depend on the state's estimated450,000 contract workers to work as drivers to keep their businesses running.The workers are considered independent contractors;they choose which hours and days they want to work.The lawsuit argues that the new law covers some industries– like ride-sharing and delivery – but not others that operate similarly.It also states that the rules violate workers' rights to choose how they earn a living.The lawsuit also argues that the new law harms companiesproviding independent services "by denying their constitutional rightsto be treated the same as others to whom they are similarly situated."The lawsuit described a study that suggested the law would increase Lyft's operating costsby 20 percent and cut the number of drivers in California by about 300,000.Democratic state lawmaker Lorena Gonzalez of San Diego helped write the bill.She said the law is meant to extend employee rightsto more than a million independent workers who lack benefits.Those benefits include a minimum wage, paid time off and medical coverage.Gonzalez noted that Uber had sought to receive exemptions to the lawwhen legislators were working on the bill.Uber joined Lyft and DoorDash in promising to spend $30 million eachin an effort to have the law overturned by voters during the 2020 election.Gonzalez said in a statement: "The one clear thing we know about Uberis they will do anything to try to exempt themselves from state regulationsthat make us all safer and their driver employees self-sufficient."She added: "In the meantime, Uber chief executives will continue to become billionaireswhile too many of their drivers are forced to sleep in their cars."