The number of council staff needing time off because of stress has shot up 60 per cent since the recession has taken hold.

Last year 97 staff members took the equivalent of 1,481 days off work due to stress, compared with 61 people taking 1,214 days off in 2008-09, according to figures obtained using the Freedom of Information Act.

Union leaders blamed redundancies, and changes to working conditions as the council seeks to merge services with neighbouring boroughs.

Nadine Houghton, from the GMB union in Kingston, said: “Managers and councillors can underestimate what is essentially a hidden illness.

“Sometimes what a person may say to a manager is quite different to what they may feel as there is an element of fear.

“Our concern is what Kingston Council is doing is creating quite general job roles and fewer specialists.

“There is a requirement staff have to carry out more work on a broader scale, and there are concerns about mergers with other councils, which adds to the stress.

“People do not want to say they cannot do this as they are worried about their job.”

A total of 65 staff were made redundant last year, compared with a previous high of 37 in 2007-08, although the council denied there was a causal link between the two sets of figures.

The number of staff days lost due to stress was 2,774 five years ago but, despite the council cutting hundreds of posts, the number of staff absent through stress has almost returned to the 2006-07 level of 106.

A spokesman for Kingston Council said: “We have almost halved the amount of staff time lost to absences due to stress in the past five years and the number of staff affected has also declined.

"Not all stress is work-related and our staff, like other people, are vulnerable to non-work related stress too.

"Kingston Council does have a good support for staff who suffer stress, irrespective of whether it is work-related, and it has been instrumental in halving the staff time lost due to stress."