Forty laboratory technicians who claim they are suffering from "extreme fatigue" after working 90 hours a week, are taking legal action against the National Health Service.

The Manufacturing Science and Finance union - the MSF - is acting for the technicians. It says the long hours break the UK Government's new Working Time Directive which seeks to limit the amount of time people spend at work.

The technicians work at the Royal Victoria Infirmary in Newcastle and are employed by the Newcastle Hospitals Health Trust. If successful, the MSF union plans similar cases across the country.

The MSF is taking the workers' cases to an employment tribunal, alleging breaches of the Working Time Regulations.

No rest

The staff claim they have been denied their rights to rest breaks and that one worker was involved in a car accident recently because of over tiredness.

Roger Kline, the union's head of health, warned that the health of workers as well as patients was being threatened.

"We are extremely concerned about the parlous state of this most specialised and highly trained, but under-valued profession," he said.

A hospital spokesman said talks would be held to try to negotiate an agreement.

Low pay

The MSF complaint comes as the union prepares to stage a lobby of Parliament to warn of an NHS staffing "crisis" due to low pay.

"A graduate scientist can earn more scanning beans in a supermarket than they can scanning for terminal illnesses in a hospital," said Roger Lyons, General Secretary of the MSF.