The business secretary, Grant Shapps, says there has been a lack of cooperation between striking workers and the government, making it difficult for the Armed Forces to provide cover.
Speaking on Sky News about the nurses strikes he said:
"We have seen the situation where the Royal College of Nursing very responsibly before the strikes told the NHS, ‘This is where we are going to be striking,’ and they are able to put the emergency cover in place".
However, he has criticised the ambulance unions for not giving them the information to ensure the Army can cover them.
He said he was "concerned" that the ambulance strikes will put lives at risk as they have failed to provide details of where they will be striking and there hasn't been co-operation "between the back-up services - typically the Army - and the people who are striking."
He went on to say that it "leaves the army, who are driving the back-ups here, in a very difficult position, - a postcode lottery when it comes to having a heart attack or a stroke when there is a strike on."
Last year the MOD accepted a request from the Department of Health and Social Care under the Military Aid to the Civil Authorities process, also known as 'Maca'.
This resulted in six hundred military personnel provided cover for the thousands of ambulance workers taking strike action across England and Wales.