Birmingham's council housing department has been dubbed the sickest in the land after it emerged that officials take an average three weeks a year off work ill.
Absenteeism among the 1,600 employees peaked in October last year at 21.3 days per person. The figure has since been reduced to 17 days, but is substantially higher than the nine-day city council average.
Opposition Labour councillors are calling for the resignation of John Lines, the cabinet member for housing.
Peter Kane, the shadow cabinet member for equalities and human resources, said that absenteeism in the housing department had risen "astronomically" from 12.9 days at the beginning of the financial year.
Coun Kane (Lab Kingstanding) added: "I lay the blame for this atrocious performance firmly at the door of Councillor Lines. I do not believe there is a higher figure for absenteeism anywhere in the country.
"His poor performance and management saw sickness rise to a whopping 21 days in October. He should now take responsibility and resign."
Councillor Lines (Con Bartley Green) said last night that he would be staying put, adding that sickness levels were even higher when Labour controlled the council. He blamed union officials for failing to take absenteeism seriously.
Coun Lines added: "We have tried sickness management but Unison don't appear to be playing ball. They are resisting any kind of management."
The council's performance in tackling sickness levels was criticised in the Audit Commission's corporate assessment report.
Inspectors described targets for cutting absenteeism as "modest". Reductions in the overall council sickness rate appeared to have stalled and the lack of sustained improvement meant that opportunities for efficiencies were being missed, the commission added.
A council spokeswoman said Birmingham was performing well in comparison to other large UK cities.
She added: "The nature of the work carried out by the council is such that some departments will be more likely to have higher absence levels.
"For example, staff working in our adult care homes have to minimise the risk of infection to vulnerable clients. Accordingly, we would expect to see differentials in the levels across some front line service areas.
"The council is always conscious of the need for continued efforts to tackle areas where improvement can be made."
Innovative steps to improve absence rates included occupational health, the StaffCare counselling service and the Getting Better Together initiative, the spokeswoman said.
Trade unions were working with HR officials to review the managing attendance policy.
The spokeswoman added: "This has led to various activities to support employee wellbeing one of which, a self-rostering system, has empowered employees to choose the hours they work and seen improvements in quality of service and a reduction in the need for agency staff."
Councillor Alan Rudge (Con Sutton Vesey), the cabinet member for equalities and human resources, said: "We are making positive steps forward and I am confident that we can retain our position as top performing core city. Reducing staff sickness level has been and will continue to be a priority."