"Tesla will now move its HQ and future programs to Texas/Nevada immediately," the CEO tweeted.

The company was filing a lawsuit against Alameda County, he added.

The county's health department had refused to let the Tesla factory reopen on Friday, citing lockdown measures.

According to figures from Johns Hopkins University, 2,715 people in California have died with coronavirus.

Since 23 March, all but "basic operations" have been suspended at Tesla's Fremont plant, near San Francisco, because of "shelter in place" orders enacted in Alameda County. The factory employs more than 10,000 workers, and makes about 415,000 vehicles every year.

California's government has eased some restrictions around the state this week, allowing businesses to resume operations. But several Bay Area counties have issued their own criteria for which businesses may reopen, which take precedence.

In Alameda, all but essential businesses must remain shut until the end of May.

Mr Musk suggested the factory's future could now be in doubt, tweeting: "If we even retain Fremont manufacturing activity at all, it will be dependen[t] on how Tesla is treated in the future."

In a statement released before Mr Musk's tweets, Alameda County said: "We welcome Tesla's proactive work on a reopening plan, so that once they fit the criteria to reopen, they can do so in a way that protects their employees and the community at large."

Mr Musk, 48, who welcomed a baby with Canadian singer Grimes earlier this week, wiped $14bn (£11bn) off Tesla's value on 1 May after tweeting that its share price was too high.

He has donated over 1,200 ventilators to hospitals in the US to assist with treating coronavirus patients.

The tech billionaire has also poked fun at the mass purchasing of toilet paper when the pandemic began. But he has also sparked controversy for promoting an unproven treatment for the virus, and for asserting, falsely, that children are "essentially immune".

Mr Musk has continually voiced his opposition to "fascist" lockdown measures, tweeting "FREE AMERICA NOW" last month.

Tesla has suspended operations at its plant in the Chinese city of Shanghai, according to Bloomberg. It had previously closed the factory as a temporary measure when the virus was at its peak in China.

The company reported a net profit in the first three months of this year, and its stock has risen to nearly $820 (£669; €756). But analysts expect the coronavirus pandemic will adversely affect its earnings in 2020.