The amendment drafted by the district would allow charter schools to apply to add grades and expand enrollment only when their operating charter is up for renewal - generally every five years.

Currently, the commission considers requests from charters on an ad hoc basis and has no policy for evaluating them. The commission has approved changes before a charter is up for renewal.

The district's proposal would require charter schools seeking expansion to demonstrate strong academic performance, successful management, and good financial track records. The charters would also have to show that their facilities could accommodate the requested changes.

The proposal has galvanized opposition from the city's charter community.

Representatives from nearly half of the district's 67 charter schools lambasted the proposed changes at a similar forum last month.

Charter leaders said the proposal would limit their independence and violate a state law that says districts cannot cap schools' enrollment after they have received their charters.

District officials have said they believe their proposed policy does not violate the law. Unlike other districts, all of Philadelphia's agreements with charter schools contain enrollment maximums, and the schools have agreed to those terms, district officials have said.

The five-member commission is expected to take up the proposed changes later this fall.

Tuesday's forum will be from 6 to 8 p.m. at the district's Education Center, 440 N. Broad St. Those wanting to address the forum should sign up by calling 215-400-5638 by 4 p.m. Monday.

The proposed charter changes can be found at www.philasd.org/charterpolicy