California Democrats are poised to pass landmark employment legislation over the objections of two of the companies that would be most affected: Silicon Valley ride-sharing giants Uber Technologies Inc. and Lyft Inc.

The bill already passed the State Assembly 59-15 and is expected to be voted on in the state Senate before the legislative session ends on Friday, possibly as soon as Monday night. Democratic Gov. Gavin Newsom has said he would sign the bill, which intends to force companies that rely on “gig workers” to reclassify them as employees, likely upending the business model of those companies.

Uber and Lyft have spent much of the year pushing lawmakers to alter the bill or exempt them. That effort has failed against opposition from labor unions and a large Democratic majority in Sacramento. The companies have argued the bill would introduce new costs and logistical challenges that would be bad for them and many of their employees, who prefer job flexibility. If the measure becomes law, it is expected to have national repercussions given California’s economic importance and history of creating precedent-setting business regulations.