In July, Personnel Today revealed the government had drawn up plans to extend the length of time staff could be off sick without a doctors' note from five days to 14 days to ease the workload on GP surgeries when the pandemic worsens.

A Department of Work and Pensions spokesman said: "If extended the same rules would apply as with five days self-certification so it would cover all illnesses."

But HR directors have warned that the move will be open to abuse by workers. Francesca Okosi-Arimah, director of support services at East Thames Housing Association, told Personnel Today: "It's overkill. To extend self certification for anything other than swine flu would be a serious mistake.

"It's unreasonable and will lead to abuse and ultimately when businesses are being encouraged to reduce absences, it's not helpful."

Sean Wheeler, group director of people development at Malmaison hotels, added: "Two weeks self-certification for any illness is opening the flood gates for people who don't have a strong work commitment or are not happy at work to abuse this."

Meanwhile, Moira Brown, HR director at care provider Care South, said the proposal would lead to additional costs in covering longer periods of absence in terms of sick pay provisions and agency usage.

However Ben Willmott, employment relations adviser at the CIPD, said the plan made sense. "Concerns that people will use swine flu to pull a sickie are overblown. Our research shows only a minority of employees take time off sick unnecessarily," he said.

"It will be a small proportion of employees that will take advantage of the situation, but the important thing for employers is to manage sickness well and keep good data on absences."