Five of six Democratic mayoral candidates have called for the School Reform Commission to reject 39 charter-school applications to be considered on Wednesday.

Only State Sen. Anthony H. Williams, long a charter-school champion, voiced no opposition to the vote.

"A blanket moratorium on charter expansion makes a nice headline, but it's really just a political solution to an education problem," Williams said in a prepared statement. "We need solutions that make sense for our children, first and foremost."

Four candidates - former mayoral aide Doug Oliver, former Common Pleas Judge Nelson A. Diaz, former City Councilman James Kenney, and former District Attorney Lynne M. Abraham - supported a moratorium on adding more charters; the city currently has 84.

Abraham said a moratorium should stay in place until "the next mayor is elected." The others urged holding off on approval of new charters until the Philadelphia School District's ongoing funding crisis was resolved.

T. Milton Street Sr. - who was set to officially launch his mayoral run Tuesday but delayed his announcement because of the weather - said he also opposes further expansion of charter schools, in principle.

"I would not disassemble the charter schools that are already in play, but absolutely no more," Street said. "There has to be quality education for everybody."

The SRC is set to vote on new charter applications at its Wednesday meeting. A key argument against further expansion of the city's charter schools is the loss of School District funding when a student transfers from a public school to a charter. The School District has calculated that cost at $7,000 per student.

In statements supporting their opposition to new charters, Abraham, Kenney, Diaz, and Oliver all referenced the potential financial impact on the district's budget.

"The apparent haste to approve new charter schools is unwarranted, and will virtually break the back of the school budget already under considerable stress," Abraham's statement said. "The rapid growth of charter schools has imperiled our children by removing huge amounts of money from the public school system."

Abraham added her name, as did Diaz and Kenney, to a petition by a group called the Philadelphia Coalition Advocating for Public Schools urging the SRC to vote "no" on new charters given the district's looming $80 million budget shortfall.

Diaz and Kenney said they were not opposed to charter schools in general, but were concerned with the financial implications of more schools now.

"We have to stop pitting charters against traditional public schools," Kenney's statement said. "But that battle will not end until building a new charter does not divert critical funding from our public schools."

Said Diaz: "I have nothing against charter schools themselves . . . but our broken funding formula robs Peter to pay Paul."

Oliver's statement said in part that the applications should be reevaluated "after there's been an opportunity to have a discussion about this year's funding shortfall, as well as the impact on future budget years."

Although Williams opposed a moratorium, he said concerns about the district's finances were justified.

"There are high-performing charters that deserve to expand," he said, "but I also believe that we cannot continue to fund charter expansion without finding ways to pay for it."

Williams, whose 2010 gubernatorial campaign received millions in donations from a trio of well-to-do charter supporters, said he favored restoring state funding to reimburse the district for the cost of a student transferring to a charter.

He said the district also should consider the one-time offer of up to $35 million from the nonprofit Philadelphia School Partnership (PSP) to help bridge the funding gap for charter schools.

The other candidates, save Oliver, are against taking the PSP money. Oliver believes the offer warrants more examination.