Nurses uniforms were changed from a dress to tunic and trousers

Up to �400,000 from the multi-million pound endowment fund was released in 2004 to purchase the new outfits.

Unions called it a "scandal" that money bequeathed by the public had been used to "subsidise" main budgets.

NHS Tayside said the decision to move from dresses to tunics was taken in response to staff safety fears after a nurse was sexually assaulted.

Pauline Dunnery's colleagues had complained the see-through white dresses they wore put them at risk following a knife-point attack on her at Perth Royal Infirmary.

Charitable funds

The nurse gave up her right to anonymity to join the Unison union's staff safety campaign.

Unison's Robin Hunter said: "It is a scandal that monies which were donated for the benefit of patients and staff are being used instead of expenditure from the main budget.

"There's no suggestion that anybody's done anything unlawful.

"It's more about the spirit of what charitable funds are meant to be for, and that is not to subsidise core expenditure.

The endowment fund is there for the comfort and well-being of patients and staff Shona Singers NHS Tayside

"I don't see how anyone could possibly argue that nurses' uniforms are not core expenditure."

NHS Tayside confirmed that money from the charity fund had been spent on new clothes for staff, which was not against any rules.

Head of communication Shona Singers said: "The endowment fund is there for the comfort and well-being of patients and staff.

"In this case the trustees decided, following a serious incident at one of our hospitals, that the routine nurses uniform replacement programme should be escalated.