A battle is raging in City Hall over the latest round of property reassessments and now, a faction of City Council members have introduced a new weapon in the fight: their votes.

As the city’s laws now stand, the Philadelphia Office of Property Assessment is responsible for setting the values that determine how much property tax an owner pays. But last week, City Councilman David Oh proposed a bill that would change the city’s charter to give Council members the power to approve or reject reassessments if they exceed the national urban Consumer Price Index — a cost-of-living measure set by the United States Bureau of Labor Statistics.

The rate of change reflected in the CPI rarely, if ever, hits the levels of OPA’s most recent reevaluation, which increased assessments about 10.5 percent for the average single-family home in the city and as much as 47 percent in fast-developing neighborhoods like Brewerytown and Strawberry Mansion.

By way of comparison, the national urban CPI increased 2.2 percent between February 2017 and February 2018, so if the proposed law were on the books at the time of the 2018 reassessment, it would be subject to a vote from Council. As things stand today, the council’s power over assessments is limited to political attacks and delay tactics. Most recently, Council hired an independent auditor to assess the OPA determinations.

“This legislation would basically give Council veto power over untrustworthy assessment practices,” said Matthew Pershe, legislative aide to Oh.

Oh’s argument for why the council should have this power, backed by Councilmembers Mark Squilla, Kenyatta Johnson, and Allan Domb, boils down to the fact that Council must approve tax increases, and they see the reassessments as a “backdoor” tax hike, Oh said in a public statement released on Friday.

“The 2019 real property assessments amount to a big real estate tax revenue increase without a real estate tax rate increase—essentially a backdoor tax increase,” Oh said. “While Council must approve any real estate tax rate increase, it currently cannot ratify any new assessments.”

Oh’s proposal is likely to face opposition. Kevin Gillen, senior research fellow at the Lindy Institute for Urban Innovation at Drexel University, said that there is often good reason for an independent body disconnected from elected officials to administer assessments. That separation encourages “assessed values [to] be set in an objective and disinterested way,” he said.

“Many Pennsylvania municipalities have a long and storied history of using the assessment process to reward neighborhoods that vote for the party in power and punish those that don’t,” Gillen said. “While it’s important to have accountability and accuracy in the assessment process, it’s also equally important to avoid its politicization and retain its independence. Admittedly, it’s a difficult and fine line to walk.”

If the amendment moves forward, Philadelphia residents would have the chance to vote for or against it at the ballot in November. It would not retroactively affect assessments made before the charter change.