The sharpest rise was in Grampian University Hospitals NHS Trust, increasing from 66 recorded attacks to 720.

The biggest increase was in Grampian

Unison lead nursing officer, Bridget Hunter, said: "This level of violent attacks on NHS staff is totally unacceptable.

"While we recognise that as a result of certain illnesses, aggressive violence can occur, what we are not prepared to tolerate is disrespect of NHS staff by some members of the public.

"For example, in South Glasgow Trust, more than half of all recorded incidents were physical assaults.

"The figures also took account of the fact that, if staff accepted that the behaviour was attributable to the medical condition of the patient, these incidents went unreported and are therefore unrecorded."

More than half the trusts in Scotland responded to the survey, with only Dumfries and Galloway Primary Care NHS Trust and Renfrew and Inverclyde Primary Care Trust showing decreases over the period.

The union is recommending:

• Standardised procedures in the recording of violent incidents

• A training budget to be allocated from each trust

• Formalised counselling and support for victims of violent attacks