A ban on federal Health Department employees taking cigarette breaks has been criticised as a heavy-handed measure that may be difficult to legally enforce.

From February 1, employees will be banned from smoking during work hours or ''when representing the department in any capacity'', according to a memo sent to staff at Christmas.

Staff will be permitted to smoke only during meal breaks, but not within 15 metres of the workplace, in a move aimed at improving their health and the ''professional reputation of the department'', the memo said.

Anti-smoking campaigners are hopeful the policy will be the first step towards a nationwide ban on public servants taking cigarette breaks.

The policy directive, issued by the secretary of the Australian Department of Health and Ageing, Jane Halton, said the ban was on ''all employees while they are on duty (apart from official meal breaks) or when representing the department in any capacity''.