Mr Brown pledged during his pre-Budget speech that specific targets would be set for each government department to reduce rates of absenteeism by 20 per cent by 2001 and 30 per cent by 2003.
He added that currently pounds 6bn a year was lost to the public sector through absent employees.
Mr Brown made clear during his speech that Peter Mandelson, the Trade and Industry Secretary, was behind the measures and would address the issue in his forthcoming White Paper on competitiveness.
But Rodney Bickerstaffe, the general secretary of Unison, the union representing 1.3 million public sector workers, urged the Government to consider "rehabilitating staff, not sacking them.
"A major priority is tackling the causes of staff sickness, including poverty, work-place violence, stressful workloads and staff shortages," Mr Bickerstaffe said.
Public sector workers had higher than the average absence rate for sickness because they had face-to-face dealings with those sections of society with the most problems. "The way forward is working in partnership with better occupational health resources devoted to rehabilitating staff, not sacking them," Mr Bickerstaffe said.
"Setting hard targets and other punitive policies will merely force sick people back to work. Do patients really want to be treated by sick nurses on the wards?"
Mr Mandelson said that he wanted the UK to be one of the world's richest nations.
"Low productivity is holding us back from achieving that goal," he added.Reuse content