SACRAMENTO, Calif. — California is off the hook from a proposal that would have required it to slash petroleum-based fuel usage by 50% in 15 years.

The sponsor of an ambitious climate-change bill in California cut the key provision from the plan this week, much to Gov. Jerry Brown’s dismay.

The Clean Energy and Pollution Reduction Act of 2015 (SB-350) was introduced in February by California Senate leader Kevin de León. The bill had originally directed the California Air Resources Board (CARB) to take actions leading to a 50% reduction in motor vehicles’ petroleum use by Jan. 1, 2030. This was a key goal for Brown and a highlight of his inaugural speech earlier this year.

According to the Los Angeles Times, the bill had passed the Senate in one piece but could not garner enough support from moderate Democrats in the State Assembly because of opposition to the fuel-reduction provision, which they worried would raise gasoline prices and hurt motorists.

De León removed it to ensure the passage of the remaining parts of the bill, which include measures to increase renewable energy’s share of electricity production and sets targets for electricity and natural-gas efficiency savings and demand reduction.

Supporters of the fuel-reduction goal blamed opposition from the oil industry, which had launched a TV and radio campaign against it, labeling the bill “The California Gas Restriction Act of 2015.”

“We reached for something grand,” said de León. “But in the end, we could not cut through the multimillion-dollar smokescreen.”

While the bill’s proponents had proposed tweaking the gasoline provisions last week to make them more flexible and add some limits to CARB’s powers, they could not reach a consensus with its opponents.

However, CARB officials said they could use policies already in place to keep moving the state toward the fuel-reduction goal. These include current efforts to reduce fuels’ carbon content, improve vehicle fuel efficiency and grow mass-transit infrastructure.

The Western States Petroleum Association (WSPA), Sacramento, released a statement praising the decision to remove the fuel-reduction provision from the bill.

“WSPA and its member companies remain committed to working with Gov. Jerry Brown and legislators on climate change and energy policy,” said WSPA president Catherine Reheis-Boyd. “Today’s announcement was an acknowledgement that California’s energy future, economic competitiveness and environment are inextricably linked.”