The army has put 20,000 troops on standby ready to be deployed to Britain’s streets, hospitals and other key sites to help tackle the coronavirus pandemic.
Around 10,000 troops are being held at "higher readiness" in case of a civil emergency and this figure will be doubled in the effort to support public services, the Ministry of Defence (MoD) said.
They will be on standby to provide support to the NHS, including tank drivers being used to transport vital oxygen supplies, the MoD confirmed on Wednesday night.
It comes after Boris Johnson earlier refused to rule out the possibility of “further and faster measures” to control the spread of the virus in the capital, where the epidemic is running ahead of the rest of the nation.
Defence Secretary Ben Wallace said: “The men and women of our Armed Forces stand ready to protect Britain and her citizens from all threats, including Covid-19.
"The unique flexibility and dedication of the services means that we are able to provide assistance across the whole of society in this time of need.
“From me downwards the entirety of the Ministry of Defence and the Armed Forces are dedicated to getting the nation through this global pandemic.”
The Ministry of Defence said it was "fully engaged" with all levels of Government to work out how the military can provide a support role over the coming weeks and months.
Meanwhile, a Written Ministerial Statement will be laid in Parliament on Thursday for the call out of the reserve forces.
Major General Charlie Stickland, assistance chief of the Defence Staff Operations and Commitments, said: "Putting more personnel at a higher state of readiness and having our Reserves on standby gives us greater flexibility to support public services as and when they require our assistance."
As part of the plans, 150 military personnel will be trained to drive oxygen tankers should the NHS require support in this area.
Maj Stickland said: "The Covid Support Force, potentially drawing upon our highly skilled scientists at Defence Science and Technology Laboratory or oxygen tanker drivers, will form part of a whole force effort to support the country during its time of need.
"Our servicemen and women are committed to maintain our operational output and delivering any support the Government requires."