Up to 20,000 service personnel will be put on standby to help combat the coronavirus, with troops gearing up to drive oxygen tankers, support the police and boost hospital capacity.
On Thursday, reservists will be put on notice to mobilise if required as part of a war-like effort to prepare the armed forces in case the government calls upon them in large numbers.
Commanders are taking steps to isolate or quarantine personnel on the UK’s most important security missions – such as the ability to respond to a terrorist attack or to protect UK skies from hostile aircraft – to ensure they are not sick.
In addition, all holiday leave has been cancelled for troops deployed on operations overseas, while training exercises in Canada and Kenya have been postponed.
The men and women of our armed forces stand ready to protect Britain and her citizens from all threats, including COVID-19, Defence Secretary Ben Wallace said.
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.
Soldiers, sailors and airmen are already helping other government departments and local authorities with their planning for the pandemic.
But the military input could rise significantly if the crisis escalates and the government is forced to call on the Ministry of Defence for assistance.
In anticipation, up to 10,000 soldiers, sailors, airmen and Royal Marines will be put on a higher readiness to mobilise.
This is on top of a force of about the same size that is already on standby to respond to any emergency in the UK – so a doubling of capacity.
Reservists could be required to step up in specialist roles, such as engineers or technicians.
Many of the doctors and nurses in the armed forces are reservists who work already for the NHS.
Boosting the UK’s capacity to deal with an anticipated spike in demand for hospital beds is an area that the armed forces is offering advice on.
Planners are looking at options possibly to convert a hotel into a makeshift medical facility or perhaps military barracks. The armed forces could even set up tented field hospitals or use a hospital ship.
A decision has already been taken to train 150 service personnel to drive oxygen tankers to support the NHS if required. They will begin training on Monday, the MoD said.
Also getting involved are scientists from the Defence Science and Technology Laboratory at Porton Down. They are supporting efforts to understand the virus and tackle the spread.
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, said Major General Charlie Stickland, Assistance Chief of the Defence Staff Operations and Commitments.
Our servicemen and women are committed to maintain our operational output and delivering any support the government requires.
But he added the demand from the coronavirus comes at a time when the military is already stretched following decades of cuts in manpower and equipment.
Military chiefs must also deal with the expectation they could lose up to 20% of service personnel at peak periods of the pandemic due to illness, the need to care for family members or the need to self-isolate, according to defence sources.
The codename for the push to deliver COVID-19 resilience to the military’s operations at home is known as Operation Rescript.
The effort to do the same for defence activities overseas is Operation Broadshare. This also includes support for the UK’s overseas territories such as the Falkland Islands.
Both involve giving support to the rest of government if needed.
General Sir Richard Barrons, a former senior commander, said the Ministry of Defence will have plans in place to ensure key tasks to protect the country are still able to function even with the virus making some troops sick.
The military is used to thinking about force protection. They know that the enemy has a vote, he said.
Sir Richard said that while the military will have to build up resilience even further around core operations like the nuclear deterrent and the ability to respond to a terrorist attack, it could reduce activities in other areas such as training.
But that has a knock-on effect on readiness of people to do things in the future, he said. Another thing you cannot stop is recruiting as the military will empty out fast.