SACRAMENTO, Calif. — Furious about oil companies’ supersized profits after a summer of record-high gas prices, California Gov. Gavin Newsom on Dec. 5 will formally start his campaign to punish big producers by asking the Legislature to fine them and give the money back to drivers.

Diesel supplies are so tight heading into winter that profits for producing the heating and trucking fuel are nearing a record high.

The national average price for diesel fell another 5.3 cents Oct. 3 to reach $4.836 a gallon, according to the Energy Information Administration.

Retail gasoline prices in the U.S. have posted their first increase — albeit very modestly — after a 98-day streak of declines, suggesting consumers won’t get much more relief at the pump. Prices now stand at $3.681 a gallon, according to auto club AAA.

Officials within President Joe Biden’s administration are hunting for ways to head off a feared spike in oil prices later this year, including the possibility of an additional release from the nation’s emergency crude reserves.

The Biden administration is warning refiners that it may take “emergency measures” to address fuel exports as stockpiles of gasoline and diesel fuel remain near historically low levels in the Northeast.

The global diesel market looks set to get even tighter as power generators and industrial users seek relief from surging natural gas prices.

Gasoline prices in the U.S. have fallen for 70 days straight, the longest down streak since January 2015.

The OPEC oil cartel and its allies decided Aug. 3 to boost production in September by a much slower pace than in previous months at a time of high gasoline prices and unstable energy supplies exacerbated by Russia’s war in Ukraine.

The White House said it expects further oil supply increases from Saudi Arabia after President Joe Biden met with the kingdom’s rulers.