Shadow health minister Mike Penning said there were 12,500 assaults on NHS staff in 2007-08, but only 700 criminal sanctions were handed out to the offenders.
He said: "That's not prosecutions, that's just sanctions. Some of them were just cautions. Where is the zero tolerance this Government promised to protect our emergency services?"
During Commons question time, Mr Penning said staff went to work in the NHS to care for the community, but they are being "assaulted by cowards in this country".
In response health minister Ann Keen argued that the Government is taking "serious measures for serious times" and prosecuting offenders was not something "we dismiss in any shape, way or form".
She said violent attacks on NHS staff are something "for all of us to address" and the Government is working with the Crown Prosecution Service and the police to get more prosecutions.
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