Goodwood, England - UK car manufacturers will be asked to switch production and start making ventilators as Britain is put on a wartime footing.
The government has issued an unprecedented peace-time "call to arms", asking firms including Rolls-Royce and JCB to join a "national effort" to produce equipment for the NHS.
Health Secretary Matt Hancock said he could not guarantee the health service has enough ventilators if the epidemic gets worse.
He added: "We now need any manufacturers to transform their production lines to make ventilators. We cannot make too many."
Ventilators are used in intensive care units to take over the breathing of critically ill patients and Mr Hancock said the NHS needed them more than anything else.
Because coronavirus is a respiratory illness, many severely affected patients are unable to breathe independently.
Mr Hancock said: "We start with around 5000 ventilators, we think we need many times more than that, and we are saying if you produce a ventilator, then we will buy it.
"No number is too high. They are relatively complicated pieces of kit... but they’re not so complicated that the advanced manufacturing that this country is so good at now can’t be able to turn its production lines over to.
"We’ve been talking to a whole host of companies about it. Ventilators are the thing that we are going to need, and frankly, right across the world, the demand for them is incredibly high, so it is not possible to produce too many.
"So anybody who can should turn production and their engineering minds over to the production of ventilators."
The British Medical Association said the UK lagged behind other European nations in terms of the number of critical care beds available.
Four in five of the 4123 adult critical care beds in England were occupied before coronavirus even arrived in the UK, official figures show.
BMA chairman Dr Chaand Nagpaul said: "Our starting position unfortunately has been far worse than many other European nations – we have about a quarter of the critical care beds that Germany has, as an example, so it’s really important that we see transparently what plans the Government has to expand that capacity."