Elon Musk and local health officials in California clashed on Saturday over the timing of the reopening of Tesla’s factory in Fremont, with the company’s chief executive pushing for an immediate return and the county’s government seeking a delay of about a week.
In a series of tweets, Mr. Musk said he would move the company’s headquarters out of California to Texas or Nevada.
The tweets came a day after health officials from Alameda County told Tesla that it was not yet allowed to resume production of electric vehicles in Fremont because of fears that the coronavirus could spread among the company’s workers. Manufacturers have been allowed to restart work in other parts of the state that have had less severe outbreaks of the virus.
“Frankly, this is the final straw,” Mr. Musk said on Twitter. “Tesla will now move its HQ and future programs to Texas/Nevada immediately. If we even retain Fremont manufacturing activity at all, it will depend on how Tesla is treated in the future.”
In a separate tweet, Mr. Musk said Tesla would file a lawsuit against Alameda County.
“The unelected & ignorant ‘interim Health Officer’ of Alameda is acting contrary to the Governor, the President, our Constitutional freedoms & just plain common sense.”
Scott Haggerty, the county supervisor for the district in Alameda County where Tesla’s Fremont plant is located, said on Saturday that he had been confident that county health officials and Tesla executives were close to an agreement on reopening the plant on May 18. But, Mr. Haggerty said, that appeared to be unacceptable to Mr. Musk, who wanted to open the plant on May 8.
“We were working on a lot of policies and procedures to help operate that plant and quite frankly, I think Tesla did a pretty good job, and that’s why I had it to the point where on May 18, Tesla would have opened,” Mr. Haggerty said. “I know Elon knew that. But he wanted it this week.”
General Motors, Ford Motor and Fiat Chrysler have all said they intend to start production May 18. Toyota expects its plants to reopen on May 11. Mercedes-Benz has already resumed operations at a sport utility vehicle plant in Alabama and a van plant in South Carolina.
Mr. Haggerty said he was working to show Alameda County health officials how Tesla would handle things like screening for the virus among workers bused in from other counties. Tesla executives and health officials were also holding conference calls to discuss the details.
Things began to break down on Thursday, Mr. Haggerty said, when a Tesla executive called him and told him Mr. Musk was thinking about suing him.
“It was only a threat, and as an elected official I get threatened all the time,” Mr. Haggerty said. “It does at that point slow down conversations between my contact at the plant and myself.”
Still, it did not appear to be game over — until Mr. Musk started tweeting.
“He could have spent time enjoying his new baby and given me and my staff a couple more days and his plant would have been open on May 18,” Mr. Haggerty said. “Am I somewhat sympathetic with Tesla? Yes I am. Am I sympathetic to the way Musk is treating people? No.”
In a statement after Mr. Musk’s tweets, the mayor of Fremont, Lily Mei, said she was growing concerned about the local economy, and she urged county officials to work with local businesses to come up with acceptable guidelines for reopening.
“We know many essential businesses have proven they can successfully operate using strict safety and social distancing practices,” she said. “I strongly believe these same practices could be possible for other manufacturing businesses, especially those that are so critical to our employment base.”
In a statement issued at about the same time, the county health department said, “We look forward to coming to an agreement on an appropriate safety plan very soon.”
Over the last few months, Mr. Musk has issued several strident calls to reopen the Fremont plant. After local officials ordered the plant closed, he tried to keep the plant open but was forced by the officials to shut it down in late March. In a conference call this past week to report Tesla’s earnings, he called the order “fascist.”
Mr. Musk has also underestimated the severity of the virus. In January, he said the coronavirus “would be no worse than the common cold.”
He is eager to get the plant running again because it produces almost all of the vehicles the company sells, and Tesla is unable to generate much revenue while it remains closed. A new, second plant in Shanghai reopened this year after Chinese officials eased restrictions on business activity.
Late on Thursday, Mr. Musk told Tesla employees the Fremont plant would open on Friday. The message was sent after Gov. Gavin Newsom said manufacturing companies could resume operations even as other businesses are to stay closed in the pandemic.
But a coalition of health officials from six counties in the Bay Area and the city of Berkeley have not yet gone that far in their most recent order, which was issued May 4.
That order allowed construction, landscaping, agricultural and other outdoor businesses to resume operations, but said that restaurants, bars or other indoor businesses “that do not permit physical distancing or have high-touch equipment” must remain closed.
“Tesla has been informed that they do not meet these criteria and must not reopen,” a spokeswoman for Alameda County, Neetu Balram, said in a statement.
When state and local orders differ, “everyone must follow the stricter restrictions,” the May 4 order said.
Alameda County has reported 1,961 coronavirus cases and 70 deaths from the disease.
The official at the center of Mr. Musk’s attacks is the interim health director for Alameda County, Dr. Erica Pan. She is also an attending physician for pediatric infectious diseases at Children’s Hospital in Oakland and has studied the course of outbreaks of antibiotic-resistant bacterial infections and their effects on communities.