Car giants BMW and Toyota are to suspend car-making at their UK plants as part of a temporary shutdown of European production.
The manufacturers join Nissan and Vauxhall in closing down factories due to falling sales and a lack of parts caused by the coronavirus epidemic.
The shutdowns mean Jaguar Land Rover and Honda will be the only big car firms left operating in the UK.
However, JLR is expected to halt production in the coming days.
BMW has about 8,000 staff in the UK. It operates a Mini factory near Oxford, as well as plants in Swindon and Hams Hall and makes Rolls Royce cars at Goodwood.
The car giant said in a statement: "Due to the rapidly evolving coronavirus pandemic we have taken the difficult decision to cease production at our production sites at Oxford and Swindon as of Monday next week [23 March] for a period of four weeks until 17 April.
"The plans for Hams Hall are under development and a subsequent announcement will be made."
It said it factory workers would be paid during the four week period, but would be expected to take the time off either as holiday, accrued overtime, or as "negative overtime" which they will "pay back" at a later date.
A Toyota spokesman said the car giant was suspending production at its European plants, including its factory at Burnaston in Derbyshire and its engine facility in Deeside.
Together the two plants employ about 3,000 people.
The staff, who will be off work from tomorrow until further notice, will be put on paid leave. The shutdown is expected to last for at least the next two weeks.
The firms join a raft of car manufacturers temporarily shutting down or scaling back European production, including:
French carmaker PSA, which owns the Peugeot, Opel and Vauxhall brands
TPSA, a joint venture owned by PSA and Toyota
Daimler, the owner of the Mercedes-Benz brand.
Sweden's Volvo Cars, owned by China's Geely.
All are struggling to get the parts they need due to travel restrictions across the continent, as well as facing a drop-off in sales as people limit all but essential social contact.
Business as usual is simply no longer an option for the European car industry. Car factories need a steady supply of parts, delivered where they're needed, when they're needed. But the upheaval across the continent caused by the Covid-19 outbreak is disrupting those crucial supply chains.
At the same time, car sales have been badly hit. If people can't leave their homes, they can't buy cars - even if the dealerships remain open. That's already had a major impact in Italy, Spain and France. It affects the UK too - because many of the cars made here are exported to Europe.
The question now is what happens next. The industry was already under huge cost pressure - spending huge sums on developing zero or low emissions vehicles in order to meet extremely stringent new emissions rules, and avoid potentially huge fines.
And for manufacturers in the UK, life after Brexit still holds major uncertainties.
A stoppage like this was the last thing the industry needed. It can weather short term disruption but the problem is, no one knows how long the disruption will last.
Jaguar Land Rover (JLR) said in a statement that it planned to continue production until at least the end of this week, if parts supplies are still available.
It added: "We will continue to closely monitor and review the situation as it evolves."
A spokesman for the firm said the health of its workforce was its "primary concern"