Butkovitz's top aide, Harvey Rice, said state law authorizes the controller to tap the paychecks of municipal workers for unpaid taxes, but the deductions are limited to 20 percent of take-home pay.
Smaller percentages will be withheld from many of those on the controller's list because of income limitations spelled out in the state law.
"We provided city employees with ample opportunity to resolve their tax delinquencies before resorting to withholding their pay," Butkovitz said in a news release. "Our initial outreach resulted in hundreds of employees paying their past-due taxes. Now we must resort to withholding . . . to force compliance."
More than six months ago, after Butkovitz and the Inquirer submitted independent requests for data on tax-delinquent employees, the Nutter administration issued a warning that city workers had to pay up or enter payment agreements with the city Revenue Department.
Roughly 1,500 have settled their debts or made payment arrangements in the last six months, but the 405 targeted for withholding ignored previous warnings, the controller's office said.
The paycheck-withholding program does not cover city employees who owe unpaid water and gas bills. Rice said the controller's office had been advised by the city Law Department that wages could not be garnisheed for utility bills.