Ministers are telling Brits only to dial 999 in the lead up to Christmas if their lives are at risk.
Their dire warning comes as 100,000 nurses begin their second 24 hour strike on Tuesday and ambulance crews walk out the following day.
Nurses have given ministers a deadline of Friday to up their pay offer or face even worse NHS disruption.
They plan to walk out again on Tuesday and say that unless the Government comes up with a deal 48 hours later others will join the 100,000 already striking.
The Royal College of Nursing is promising another round of walkouts next month hitting more hospitals and further reducing already skeleton care.
RCN leader Pat Cullen said: “Government should get this wrapped up by Christmas.
“January’s strikes will see more hospitals and more nurses taking part than at present.”
Cabinet Office minister Oliver Dowden will chair two emergency COBR meetings this week to draw up contingency plans for the industrial action.
Ambulances may not turn up to other than seriously injured or ill patients. The remainder are being ordered to call 111 or make their own way to hospitals.
Community first responders are also being asked to step in to give urgent first aid.
Health Secretary Steve Barclay said: “My number one priority is to keep patients as safe as possible.
“We are stepping up preparations including making best use of the armed forces and volunteers.”
But he said there were no plans to end the strikes with an increased pay offer to the unions.
Mr Barclay added: “Their demands are not affordable in the economic circumstances.”
Sara Gorton of Unison said: “The military’s no substitute for trained ambulance staff.
“The hours spent on contingency planning could have been better used trying to prevent the strikes from taking place “
And Sharon Graham of Unite added: “This government is guilty of criminal negligence in hollowing out the NHS.
“The strikers are actually trying to save the service”.
The Army has been forced to mobilise 1,200 soldiers to pick up the sick and injured and take over immigration checks from striking Border Force staff.
Senior officers have assigned 600 soldiers to drive ambulances with another 150 to act as back up.
A further 1,000 civil servants will join the military to check passports in a bid to keep passengers flowing through air and seaports as Border Force walks out on Friday. But long delays are expected.
Health unions have been working with the NHS to decide what safe level of care will need to be maintained during the action.
And a new Resilience plan will be published by the Cabinet Office tomorrow (mon) in a bid to counter the effects of strikes.
As disruption continues through the Christmas holidays with National Highways staging walkouts over New Year, extra traffic police have been drafted in for motorway patrols and plans for roadworks have been binned.
