TORONTO - The union representing about 5,500 Ontario jail guards says it won't agree to a government proposal to force correctional officers onto private insurance after five sick days.

The provincial auditor general severely criticized correctional officers for taking an average of 32.5 sick days in 2007, up 63 per cent from 2001.

More than 60 guards reportedly called in sick last weekend at the jail in Penetanguishene, but the Ontario Public Service Employees Union says it can't confirm that number.

Union spokesman Don Ford says all the workers could have been sick, but he admits most are simply fed up with the government's failure to address overcrowding in jails.

Ford says virtually nothing has been done to improve working conditions in jails since the government promised to address overcrowding in 1989.

Correctional Services Minister Rick Bartolucci says he's concerned about absenteeism, but adds he wants to make sure working conditions are improved so correctional officers don't have to book off sick.

The Opposition says having dozens of guards call in sick to one jail at the same time poses a threat to public safety.