Tesla Inc pn Saturday said it sued local authorities in California as the electric carmaker pushed to re-open its factory there and Chief Executive Elon Musk threatened to move Tesla’s headquarters and future programs from the state to Texas or Nevada.

Tesla has roughly 20,000 employees in the Bay area, including its headquarters in Palo Alto.

"Tesla is filing a lawsuit against Alameda County immediately. The unelected & ignorant “Interim Health Officer” of Alameda is acting contrary to the Governor, the President, our Constitutional freedoms & just plain common sense!" Tesla CEO Elon Musk wrote on Twitter.

Musk has been pushing to re-open Tesla’s Fremont, California, factory after Alameda County’s health department said the carmaker must not reopen because local lockdown measures to curb the spread of the coronavirus remain in effect.

Here is what the Alameda County’s health department said:

"The Alameda County Health Care Services Agency and the Public Health Department have been communicating directly and working closely with the Tesla team on the ground in Fremont. This has been a collaborative,good faith effort to develop and implement a safety plan that allows for reopening while protecting the health and well-being of the thousands of employees who travel to and from work at Tesla’s factory.

The team at Tesla has been responsive to our guidance and recommendations, and we look forward to coming to an agreement on an appropriate safety plan very soon.

We greatly value and support the important role of small and large businesses to our local economy and our communities. We appreciate that our residents and businesses have made tremendous sacrifices and that together we have been able to save lives and protect community health in our region. We need to continue to work together so those sacrifices don’t go to waste and that we maintain our gains.It is our collective responsibility to move through the phases of reopening and loosening the restrictions of the Shelter-in-Place Order in the safest way possible, guided by data and science."

In a blog post on Saturday, Tesla said the county’s position left it no choice but to take legal action to ensure Tesla and its employees can go back to work.

"The County’s position left us no choice but to take legal action to ensure that Tesla and its employees can get back to work. We filed a lawsuit on May 9 asking the court to invalidate the County Orders, to the extent the County claims they prevent Tesla from resuming operations," Tesla said.

The company also said it had worked out a thorough return-to-work plan that includes online video training for personnel, work zone partition areas, temperature screening, requirements to wear protective equipment and rigorous cleaning and disinfecting protocols.

The company said it had informed health authorities in Alameda County, where the Fremont factory is located, about its restart plans, but claimed the acting official did not return calls or emails.

Alameda County is scheduled to remain shut until the end of May, with only essential businesses allowed to reopen. The county said it does not consider Tesla an essential business.

“If we even retain Fremont manufacturing activity at all, it will be dependent on how Tesla is treated in the future,” he tweeted, referring to the San Francisco Bay area facility that is Tesla’s only U.S. vehicle factory.