A California lawmaker says she's giving up on her proposal to require that 15 percent of new cars be emission free by 2025.

A spokeswoman for Democratic Assemblywoman Autumn Burke of Los Angeles says the measure ran into steeper opposition than she expected.

The spokeswoman, Allison Ruff, says the opposition came "from a variety of groups including the Western States Petroleum Association," which represents oil companies.

Burke announced her proposal last week, saying California's existing zero-emission-vehicle mandates were too weak to require significant new investments by automakers. AB1108 would have made plug-in hybrid vehicles, which include a gas engine, ineligible to comply with the mandate.

Automakers characterized the legislation as a giveaway to Tesla Motors, the largest seller of electric vehicles last year.

California lawmakers meanwhile are under pressure to divvy up more than $1 billion the state has collected from carbon auctions.

But there's a deepening divide in the Legislature over whether to dole out the money now or retain it as a bargaining chip while Democrats struggle to win support for extending California's climate programs.

The top Senate leader upped the ante Wednesday when he released legislation to spend $1.2 billion â most of the money not already earmarked. The plan by Democratic Senate President Pro Tem Kevin de Leon of Los Angeles includes incentives for lower-emission vehicles, transit funding and money for energy efficiency upgrades.

His proposal puts him at odds with Democratic Gov. Jerry Brown and Democratic Assembly Speaker Anthony Rendon of Paramount, who would prefer to spend much less.

This story has been updated.