Four hundred military personnel have been deployed to hospitals in the Midlands and London to help the fight against Covid-19, the NHS has said.
They are working alongside doctors and nurses amid "unprecedented pressure" on the service.
The NHS has not said which or how many hospitals are involved, how the 400 are shared among them, or the roles armed forces members are performing.
But trusts in Birmingham, Wolverhampton and Shropshire are receiving support.
The armed forces have been involved in coronavirus operations since last year, including helping with community testing.
The government had previously highlighted about 50 military staff committed to hospitals in Kent and Essex to ensure "workforce resilience" amid increasing demand for services.
But the latest move sees hundreds more sent to the heart of England and the nation's capital to work with front line hospital staff.
An NHS spokesperson said: "The NHS is grateful to the 400 military personnel working in hospitals in the Midlands and London, alongside doctors, nurses and others who have returned to the NHS front line and tens of thousands of St John volunteers working across the country."
Shrewsbury and Telford Hospital NHS Trust, which runs an acute hospital in each of the Shropshire towns, confirmed the sites would get military medical teams, due to start this week.
The personnel will fill in for healthcare assistants, a position where there are local staff shortages due to shielding and self-isolation.
At a meeting of the West Midlands Combined Authority on Friday, the chief executive of The Royal Wolverhampton NHS Trust, David Loughton, said the military would be arriving in both Birmingham and the Black Country, including his own trust, "to take the pressure off" hospitals.
He said the armed forces would be "working under the supervision of senior clinicians and nursing teams and carrying out a variety of duties".
He added: "I believe that is similar across the West Midlands conurbation."
The NHS spokesperson said it had 50,000 more staff working in the service than a year ago, "all working round the clock to respond to unprecedented pressure".