Uber, Postmates sue to challenge California's new labor law

Ride-share company Uber and on-demand meal delivery service Postmates are suing to block a broad new California law aimed at giving wage and benefit protections to people who work as independent contractors.

The lawsuit filed in US court on Monday argues that the law set to take effect Wednesday violates federal and state equal protection and due process guarantees.

The law creates the nation's strictest test by which workers must be considered employees. It could set a precedent for other states.

Assemblywoman Lorena Gonzalez says the law extends employee rights to more than a million California workers who lack benefits.

Transport Workers Union of America responded to the lawsuit in a statement

"How many times to do these companies plan to lose this fight before they acknowledge their workers’ rights?," the wrote in part. 

The union characterized the lawsuit as a "frivolous" waste of investors' money.

Gonzalez used the hashtag "Uber greed" on her Twitter account on Monday. 

KTVU contributed to this report.