A parents' group is threatening to sue the Philadelphia School District to force it to throw patronage workers from the Board of Revision of Taxes off the school system payroll.

Parents United for Public Education made its intention known yesterday after district officials confirmed that - against their wishes - the school system would still pick up the tab for the workers.

"At some point, someone's got to be the one to say, 'Enough's enough,' " said Helen Gym, a founder of Parents United.

For years, the BRT, which assesses the value of city properties, has maintained a split payroll - 120 city workers who cannot be involved in politics and about 80 employees on the school district payroll who can politick as much as they want. The school district jobs are filled primarily by Democratic and Republican Party workers and their relatives.

The patronage jobs cost the district, which faces a revenue gap of $160 million or more, about $4 million a year in salaries and benefits.

During yesterday's School Reform Commission meeting, Gym pointed to one state law that says that the BRT must assess properties on behalf of school districts, and another that tags the county - in Philadelphia's case, the city - with responsibility for paying for the BRT.

Furthermore, if the district must continue to pay for the workers, it has the right of oversight and audit, as it does with other vendors, Gym said.

A lawsuit would be the last resort, she said.

"We'd like to see the district act," Gym told the SRC. "But we won't rule out a lawsuit."

Commissioner Johnny Irizarry asked whether paying the workers would take away money from children's classroom instruction.

"Absolutely not," said Michael Masch, chief business officer. "If that were the case, the superintendent and I would be urging you to take action now."

The BRT collects about $700 million for the school district in property taxes and business-use and privilege taxes, Masch said.

In other SRC business, Superintendent Arlene Ackerman said she wanted to revisit the policy that requires school staff to call police first if a student commits a crime.

Principals ought to decide whether police need to be called, she said.

Current procedure dictates that police must be summoned if a serious, criminal incident is committed. The practice was standardized after a series of reports pointed out that the district was underreporting school violence.

Ackerman's announcement - she said she was "disconcerted" with current policy - came during a presentation on school climate and safety.

In an interview, Ackerman said that as principal of a tough Missouri middle school, she was responsible for judging when police were to be called. Every year, there were only a handful of cases in which calling police was appropriate, she said.

"The principal ought to have the final say," she said.

Some cases are clear - when a student brings a loaded gun or a large quantity of drugs to school. Others require more judgment, she said.

But some argue that giving principals that power back is a slippery slope.

"I think it's a step backward," said Jerry Jordan, president of the Philadelphia Federation of Teachers. "I think it will lead to underreporting."

He said principals "are not trained law enforcement officers. That's why police are called, so they can make the determination."

Contact staff writer Kristen Graham at 215-854-5146 or kgraham@phillynews.com.