Atlanta Mayor Kasim Reed got heated Tuesday as he defended his efforts to reform the city’s rising pension costs.

"Enough is enough," the mayor said during a meeting with a panel he created earlier this year to study the problem.

The verbal sparring began when Lt. Jim Daws, head of the city's firefighter union, asked why the city has historically been unable to pay its employees more and provide better services. Daws feels city workers have been unfairly blamed for Atlanta's mounting pension costs, which have risen since 2001 from $55 million to $125 million, nearly one-quarter of city spending.

Reed, who took office in January, countered that the city could pay its workers more if it had not cut property taxes six times in the past decade and hadn't made changes in 2002 and 2005 that resulted in increased pension spending.

"I'm not going to take the attack for choices I did not make," the mayor said.

Daws said he was not attacking Reed.

"What I am asking is a difficult question that needs to be answered," said Daws, who is serving on the panel.

Reed and the unions differ on the mayor's plan to increase the employee vesting period for city workers from 10 years to 15 years. The unions contend Reed cannot legally change the vesting period for current workers with less than 10 years on the City Hall payroll. Reed said the move will save the city at least $8 million and prevents him from laying off any employees.

The mayor is scheduled to unveil his proposed budget Wednesday to the City Council.