SEATTLE -

Rideshare companies Uber and Lyft are leading a campaign to undo new regulations adopted by the Seattle City Council.

The rules require them to meet the same safety and insurance requirements as taxi companies. They also limit each company to 150 drivers on the road at a time, collectively capping them at 450.

Uber, Lyft and similar ventures use smartphone apps to dispatch drivers using their personal vehicles. They say the regulations would be a huge hit.

The Seattle Times reports that Uber and Lyft have each contributed more than $200,000 to a signature gathering effort coordinated by a group called Keep Seattle's Ride Options. They hope to turn in at least 16,510 signatures to keep the rules from taking effect and to require a public vote later this year.

The City Attorney's Office says it's not clear whether the rules can even be subject to a referendum.