Prospect said staff engaged on industrial relations work existed to improve the running of departments and not to engage in political activity.

“Civil servants are bound by a code of political neutrality and so are their unions,” said Paul Noon, Prospect General Secretary.

He said 99% of staff representatives received no facility time from departments beyond the standard facilities every employer is bound to provide recognised union representatives by the ACAS code of practice.

“The age of top-down management by diktat died out years ago,” said Noon. “In the modern era of constant restructuring, new working practices, manpower cutbacks and pressures on public spending, it is clearly in Government’s interest to have informed knowledge of staff views.”

Facility time, as it is called, has existed in the civil service since the 1940s and has been recognised as an aid to good management by every Government from that of Harold McMillan to Margaret Thatcher, John Major and Tony Blair.

A value for money study in Natural England this year showed that management benefited from trade union representation by six times its cost to the department.

Among benefits to the employer listed by the study were improved morale, time saved on litigation, personal cases, change programmes, grievances and handling enquiries about employment issues.