California’s mileage tax study is approaching the finish line — and a prominent Republican lawmaker warns Democrats are preparing to reach deeper into drivers’ wallets.

Assemblymember Carl DeMaio, R-San Diego, told the California Post that Gov.-elect Xavier Becerra and Democratic lawmakers are “champing at the bit” to charge motorists by the mile, potentially using annual odometer checks to calculate bills he warns could come on top of existing gas taxes.

“They’re proposing everyone does a mileage tax — and they’re not suggesting that we’re going to get rid of any of the gas taxes or car taxes,” DeMaio told the California Post.

Becerra reignited the debate during an October interview with KCRA, saying “everything should be on the table” when asked whether he would support a mileage-based tax to maintain California’s roads.

He argued that electric vehicle owners, who sidestep paying gas taxes, should help pay for the infrastructure they use.

Becerra’s campaign subsequently pushed back on characterizations that he had backed a mileage tax.

“Secretary Becerra has not proposed a mileage tax,” campaign spokesperson Jonathan Underland previously told The Post. 

Officials for Gov.-elect Becerra did not respond to requests for comment Tuesday.

DeMaio said Becerra’s willingness to consider charging motorists by the mile should alarm Californians already struggling to afford the drive to work, particularly those who live far from their jobs because housing closer to employment centers is too expensive.

DeMaio argued that Becerra’s past remarks showed more than a willingness to consider options.

“He said, ‘everything’s on the table,’ and then he started arguing in favor of it,” DeMaio said. “He literally was making the argument for the mileage tax.” 

DeMaio added, “They just want more money.”

“This has all been plotted and planned,” DeMaio said.

“Democrats know that there are all these old cars on the road, and they cannot track mileage for old cars. So, what is the backup? The backup is you’re going to have to pull your car in annually for a smog check or a mileage odometer reading, and that will be the basis of your charge.”

At 6 cents per mile, a motorist driving 15,000 miles annually would owe at least $900 before any credits or offsets, DeMaio said.

The San Diego Republican pointed to a contentious fight in his home county, where the San Diego Association of Governments adopted a regional transportation plan in December 2021 that included a potential charge on motorists for each mile driven.

Following public backlash, the agency’s board directed staff in September 2022 to prepare an amendment removing the proposed charge. The board formally adopted the amended plan in fall 2023.

The Legislature is now awaiting recommendations from a road charge pilot program that ran from August 2024 through January 2025.

The pilot tested different ways of counting miles, including odometer photographs, connected-vehicle technology and plug-in devices with or without GPS. Caltrans said participants’ personal information would be protected and destroyed after the study. A final report is due by the end of the year. 

Officials for the Department of Transportation did not respond to The Post’s requests for comment.