Britain's over-70s will be told to stay at home for four months while the government goes on a war footing to firefight the coronavirus crisis, it was revealed last night.

Mass isolating of the elderly - even if they are not ill - will begin within the next 20 days as Boris Johnson ratchets up efforts to tackle the UK's ballooning outbreak.

Although the drastic measures have been drawn up to protect those most vulnerable to the killer COVID-19 infection, it brings serious concerns about the wellbeing of pensioners cooped-up for such a long time.

Regular social outings will have to be scrapped and pangs of loneliness could compound an already stressful isolation experience, psychologists have warned.

Instructing the over-70s to remain indoors forms part of a wider package of emergency powers due to be officially rolled out by Downing Street this week.

Banning mass gatherings, allowing the police to detain suspected virus victims and forcing schools to stay open were already revealed to be part of the strategy going forward.

And last night the government's coronavirus blueprint was fleshed out further as more impending measures emerged:

* Troops will be deployed to guard hospitals and supermarkets, where panic-buying unleashed carnage on Saturday

* Thousands of private hospital beds will be drafted to relax the pressure on the NHS, which threatens to be overwhelmed as cases climb

* Business will be urged to serve the national interest by overhauling production lines to instead manufacture essential medical equipment such as ventilators

* Whole families will be told to isolate themselves even if just one member falls ill with coronavirus

* The police are planning to sideline pursuing minor misdemeanors and only investigate crimes involving a loss of life to free up officers

The government's Scientific Advisory Group for Emergencies (Sage) yesterday advised that the next interventions - shielding the vulnerable and household isolation - 'will need to be instituted soon'.

The decision to instruct all over-70s to remain in their homes and care homes within three weeks is to stop the NHS 'falling over' with pressure, according to ITV News' political editor Robert Peston who first revealed the move.

He further revealed: 'Plans are also well under way for doctors to give consultations to patients quarantined at home by video links over the internet.

'There are two other aspects of this wartime mobilisation: Army hospitals will be used (and) lockdowns of cities or parts of cities have NOT been ruled out.'

Downing Street's new raft of measures, which will be rubber stamped at a meeting chaired by the PM today, marks a screeching U-turn as only a few days ago the government flatly refused to follow European counterparts in curbing person-to-person contact.

But the public appeared to back radical measures to battle the health crisis, with a YouGov poll for the Sunday Times finding 52 per cent believe the government should declare a state of emergency. Meanwhile, 63 per cent were in favour of food rationing.

Number 10's tack to implement tougher measures came as Britain's COVID-19 death rate almost doubled overnight as ten more people died, bringing the toll to 21. The infection tally hit 1,140.

Troops will be deployed to guard hospitals and supermarkets, where panic-buying unleashed carnage on Saturday. Pictured: trolleys piled high for delivery are seen at an Asda in London

Mass isolating of the elderly - even if they are not ill - will begin within the next 20 days as Boris Johnson ratchets up efforts to tackle the UK's ballooning outbreak

British holidaymakers and students in Spain are desperately trying to return home before the country's announces the most severe coronavirus measures in Europe. Pictured: People wearing hazmat suits in downtown Madrid

Shoppers are faced with partially empty shelves at a supermarket in London as consumers worry about product shortages as a result of the coronavirus