Up to 20,000 service personnel are to form part of a Covid Support Force, the Defence Secretary has announced.
Around 10,000 troops are held at "higher readiness" in case of a civil emergency, and this figure will be doubled in the effort to support public services following the coronavirus outbreak.
The Ministry of Defence (MoD) 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.
ITV News Correspondent Neil Connery on the new military support force
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."
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."
Former serviceman and MP Tobias Ellwood told ITV's Peston said the use of military in this way would have been "planned for, this is exactly what the armed forces are there for".
The Chair of Defence Select Committee told ITV News' Political Editor Robert Peston that the military could be used for jobs such as driving tankers or ambulances, setting up emergency morgues or converting hotels into hospitals.
The news came on a day that Prime Minister Boris Johnson announced schools across the UK are to close to all pupils except vulnerable children and those of key workers in a bid to halt the spread of Covid-19.
Also on Wednesday, the number of deaths of people with coronavirus in the UK rose to 104 and the number of cases rose to 2,626, and fears were raised by hospital workers that lives were being put at risk as they were not being provided with the emergency equipment they needed.
Coronavirus: Everything you need to know