Stephanie Singer's tumultuous first term as one of three city commissioners overseeing Philadelphia elections is shaping up to be her last.

Singer had just 996 signatures remaining on her nomination petitions at the conclusion of a four-day legal challenge that ended late Thursday and won't be decided till at least next week.

She needed at least 1,000 signatures from registered Democrats in the city to stay on the May 19 primary election ballot.

But one out of every three of the 1,485 signatures she had filed on March 10 were either withdrawn or ordered stricken by Common Pleas Court Judge Joel Johnson.

Singer's lawyer, Charles Goodwin, said Johnson deferred signing an order to remove her from the ballot, giving her time to file last-minute motions to try to save her campaign.

Richard Hoy, lawyer for three Democrats who challenged Singer's petitions, said her campaign now wants to challenge the work of a handwriting expert who examined the signatures. Hoy laughed off that attempt, claiming Singer had tried to hire the expert before learning that he was working for the other side in the challenge.

Goodwin has until Monday to file his motion about the expert's work.

Hoy predicted that Singer will be yanked from the ballot, either by Johnson or through an appeal to the state Commonwealth Court.

"We expect that once everything is said and done, Commissioner Singer will be on the ballot this spring," Goodwin countered, also vowing to appeal if Singer loses this round.

Singer, 50, is a former ward leader and math professor who ran as a reformer in 2011. She soon clashed with her two fellow commissioners and with other politicians, including U.S. Rep. Bob Brady, chairman of the city's Democratic Party.

"I shouldn't be surprised," Singer said of the ballot challenge in a statement sent Friday afternoon to supporters. "After all, when you fight power, power fights back and the Philadelphia political machine certainly wants to hold onto its power."

Hoy was assisted in the long legal challenge by Nick Custodio, a political consultant working for Lisa Deeley's campaign for city commissioner. Deeley, who has worked for City Controller Alan Butkovitz and City Councilman Bobby Henon, has strong backing from the Democratic Party in her race.

"She lost because she lost," Hoy said of the challenge against Singer. "No one else did it. She put together one of the worst sets of petitions I have ever seen."

Hoy challenged 1,124 of the 1,485 names on Singer's petitions, questioning the veracity of various voters' signatures as well as the street addresses and party affiliations that voters listed. He also challenged the accuracy of addresses listed by at least one person who had circulated the petitions on Singer's behalf.

brennac@phillynews.com 215-854-5973 @byChrisBrennan