The union for professionals warned that a blanket ban across departments and agencies would hit key areas of the new coalition government agenda and ignored staffing shortages that already exist in many parts of government.

Dai Hudd, Deputy General Secretary, said: “At present there are significant numbers of vacancies in defence and all nuclear-related areas.

“The new Government has not had time to acquaint itself with these realities. But it must now mount an urgent review of core Government capability in science, engineering and related skills before imposing arbitrary cuts that will only make a bad situation worse.

“We must avoid a situation where the administrative powers at the head of the civil service dismantle the very specialist skills that are needed to deliver services on the ground.”

Hudd pointed out that the new coalition’s programme for government contains plans for additional spending on flood prevention, wildlife protection, marine conservation, food safety and other areas which could not be realised without additional investment in specialist staff.