Tesla Inc.’s electric vehicles would be shut out from consumer rebates under a proposal by California Governor Gavin Newsom, pitting the prospective Democratic presidential hopeful against Republican power player Elon Musk.

Newsom on Monday unveiled plans to offer rebates to EV buyers if US President-elect Donald Trump repeals a federal subsidy. A program California phased out in 2023 could be rebooted in lieu of the $7,500 tax credit, the governor said.

His office told Bloomberg News that the current proposal includes market-share limitations that would exclude Tesla’s popular EV models. The details — including Tesla’s possible omission from the credits — will be negotiated with the state legislature and could change, Newsom’s office said.

“It’s about creating the market conditions for more of these car makers to take root,” according to the governor’s office. It wasn’t immediately clear if other automakers would be excluded.