A hospital trust admitted it has a problem with its own staff - on the same day a health union called for action to reduce violence.

A fact-finding tour of portering and security services at the Newcastle Hospitals NHS Trust uncovered instances of aggressive behaviour by health workers directed against their own colleagues.

A party of directors and senior managers touring the trust were told that one of the day-to-day challenges faced by porters and security officers was "dealing with aggressive behaviour from members of the public and also occasionally from trust staff."

Trust chairman Sir Miles Irving, who was a member of the visiting team, has stressed that the trust board "viewed aggression towards staff as wholly unacceptable and particularly so when being exhibited by other members of staff."

News of the occasional flare-ups between health workers coincided with a statement issued by the health union Unison welcoming a call by the Public Accounts Committee to reverse the rising levels of violence and aggression against NHS staff.

Despite improved awareness and reporting of assaults MPs said more needs to be done to identify which approaches are most effective in preventing violence.

A spokeswoman for the Newcastle trust said most of the incidents highlighted by the report involved friction over scarce car parking spaces.

"It's the story of every hospital in the country, it's the one thing everyone has a problem with - car parking," she said.

"While the hospital tries to allocate spaces to staff who work unsocial hours, not everyone could be accommodated.

"At the end of the day we try to encourage members of staff to be tolerant towards other members of staff, you can't criticise the general public for being aggressive if you are being aggressive to a colleague."