Tesla boss Elon Musk is taking legal action against Alameda County and threatening to pull his US factory and headquarters out of California after officials ruled they could not reopen the electric vehicle plant.

The 48-year-old entrepreneur claimed the county health department had overstepped state and federal coronavirus restrictions when they blocked the resumption of production at its Fremont factory.

"Frankly, this is the final straw," Musk tweeted. "Tesla will now move its HQ and future programs to Texas/Nevada immediately.

“The unelected & ignorant 'Interim Health Officer' of Alameda is acting contrary to the Governor, the President, our Constitutional freedoms & just plain common sense!” he added.

The local coronavirus rulings, which were introduced on March 23, have been extended until the end of May, a spokesperson for the public health department said.

These restrictions permit essential businesses to reopen and it was ruled that Tesla did not meet the required conditions, thus prompting Musk to take legal action.

Musk was unamused that California Governor Gavin Newsom had permitted Bay Area counties to continue with these restrictions while allowing them to be relaxed elsewhere.

"The Bay Area started with a higher disease burden than the rest of the state, which may mean tighter restrictions than the rest of the state for some time," said a statement from the Governor.

“Restoring all daily activities too soon risks a rapid spike in cases and would jeopardise the relative stability we've seen in our health and hospital systems."

Musk had previously criticised the lockdown rulings as ‘fascist’ and ‘forcibly imprisoning people in their homes’ adding that the uncertainty surrounding production resumption was a ‘serious risk’ to his business.