Urgent plans are under way to turn London's ExCel conference centre into a military-supported hospital with two 2,000-bed treatment wards.
Coronavirus deaths in the UK rose to 422 on Tuesday with 87 more fatalities overnight.
Health Secretary Matt Hancock said the new NHS Nightingale hospital would open in the ExCel next week.
"With help from the military and NHS clinicians we will make sure we have the capacity we need so everyone can get the support they need," Mr Hancock said.
He said more than 35,000 doctors and nurses would be joining and rejoining the NHS on the frontline immediately.
Other venues across the country are understood to be under consideration, including the O2 concert venue, Wembley Stadium and the National Exhibition Centre in Birmingham.
The field hospital will focus on critical care for people struggling to breathe.
It is expected to be staffed by military medical personnel and NHS and private hospital staff.
Mr Hancock said the military would be distributing protective equipment to healthcare staff to reduce infection rates in the service.
Officials have warned that intensive care hospitals in London could soon become overwhelmed.
“NHS staff are working round the clock, gearing up to deal with this unprecedented global health threat," NHS England chief executive Sir Simon Stevens said.
"We’re getting on with other options too, including new facilities as well as a landmark deal with private hospitals, which has put 20,000 staff, 8,000 beds and 1,200 ventilators at our disposal.
“But it remains absolutely vital that this huge mobilisation by the NHS is matched by action from the public, which means following medical advice to the letter.
"Please stay at home to save lives.”
The ExCel, which opened in London’s Docklands in 2000, usually stages conferences, trade fairs and sports events.
