A union group helping teachers organize at Olney Charter High School has filed its fourth unfair labor practice in nine months.

The Alliance of Charter School Employees, a local affiliate of the American Federation of Teachers Pennsylvania, claims that Aspira Inc. has initiated a policy that disallows staff at Olney from circulating disparaging remarks about the school on social media.

Aspira Olney is one of three former Philadelphia school district-run high schools that was turned over to a charter operator in 2011 in an attempt to improve student outcomes.

In becoming a renaissance charter, the school shed at least half of its existing staff and all remaining faculty lost union privileges.

"As stakeholders we deserve a voice when key decisions are made. The policies and procedures and processes that they decide on affect us and they affect our students, and we just want to be basically in the room when discussions about those policies happen," said Ellen Peirson, a third-year civics teacher at Aspira Olney who's been part of a push to bring the union back to the school.

The Aspira policy says that teachers can be fired or disciplined for remarks they make or have made on social media – past, present or future.

"Basically they're trying to restrict staff members opportunity to interact with each other in the building during the day and also to interact with each other and the public even after hours on our own time," Peirson said.

"We do see this as an attempt to silence our organizing project," said Candy Lerner, executive director of the American Federation of Teachers of Pennsylvania. "I mean this is how people communicate today, they are just garnering support to be able to unionize."

ASPIRA declined to comment for this story. Since becoming a charter school, Aspira Olney has seen a small reduction violent incidents and significant increases on state standardized tests.

Geometry teacher Chris Bishop says it's misguided to attribute those advances to the school's lack of union organization. According to Bishop, Aspira's policies have cultivated climate of fear.

"If people are going to not be asked back next year, we need to have a reason for that," he said. "Even if we all agree that that teacher shouldn't be back, there should be some sort of protocol or due process that you need to follow. And not having that is pretty scary."

In order to unionize, a majority of Aspira Olney's faculty must vote for the measure. AFT officials say there's no timetable set for a vote.

"We have a strong core group," said Lerner, "and they are rallying more and more support both community wide and school wide each and every day."