Los Angeles Mayor Eric Garcetti urged California voters Wednesday to reject a ballot measure repealing a statewide gas tax.

The mayor says losing revenue collected through the tax would delay or jeopardize some of the city’s most significant transportation projects, including train service to LAX.

“Thanks to the voters of LA County who approved Measure M, we’re on the cusp of finally connecting LAX to rail,” said Garcetti in a statement. “[Proposition 6] would undo those plans.”

The ballot initiative, sponsored by a group called Reform California and backed by the state’s Republican Party, would eliminate a 12-cent tax on gas that went into effect last year and subject new gas taxes or motor vehicle fees to voter approval going forward.

Supporters argue that this would save consumers money and force California legislators to rethink financing mechanisms for road repairs and public transit. But opponents, including Garcetti, argue that funding from the gas tax is crucial to completing key transportation projects on time.

According to a financial forecast released by Metro in September, more than a dozen major projects in LA County are set to receive funding through the gas tax. They include construction of a new train station at 96th Street, where riders will be able to connect to LAX via a people mover system; a transit line through the Sepulveda Pass; a light rail line connecting the Gateway Cities to Downtown LA; and repair work and resurfacing on the 5, 10, and 605 freeways.

If efforts to repeal the gas tax are successful, Metro estimates that these projects could be delayed between three and five years. That would make it tricky for the transit agency to achieve its well-publicized goal of completing 28 projects in time for the 2028 Olympics.

According to Garcetti, these potential side effects of repealing the tax make voting against the ballot measure a “no brainer.”

Recent polling data suggests a small majority of California voters are inclined to agree. A poll released last week by the Public Policy Institute of California found that 52 percent of voters plan to vote against the measure, compared to 39 percent who say they’ll vote yes.