The call comes after a 58-year-old received compensation after she was sexually assaulted at James Cook University Hospital in Middlesbrough when she was helping a patient in the shower in June 2009.

The assault, which has left the union member suffering psychological distress, could have been avoided had a risk assessment been carried out.

The patient, who was in his 50s, had a history of assaulting members of staff but the UNISON member was not warned and was left alone with the man.

While her back was turned he grabbed her indecently, causing her pain and discomfort. Although she was forced to take several weeks off work and suffered from nightmares, counselling has enabled her to return to her job as a health care assistant. She still suffers from flashbacks when dealing with certain situations.

She said: “I find it difficult talking about the attack because it left me so distressed. I still suffer from flashbacks when I’m at work and I have to take a step back to get myself under control. If I had only been warned about this patient’s history I could have avoided getting myself into a dangerous situation.”

Following the incident she contacted UNISON which instructed its lawyers Thompsons Solicitors to pursue a claim for compensation against the hospital.

The hospital admitted liability and the case was settled for £3,500.

A spokesperson from UNISON said: “This is another example of our members suffering just for doing their job. Sexual assaults against our members are far too common and too many, like this one, could be prevented with better communication and procedures in place.

“We will continue to campaign for better protection for our members at work and zero tolerance of sexual assaults against staff.“

Diane Davison from Thompsons Solicitors in Middlesbrough added: “This was a horrific incident which badly affected this member. Unfortunately we see many similar attacks in the health service and employers must work harder at basic health and safety to avoid this type of incident happening again in the future.”