Several high-profile Philadelphia-area congressional campaigns are looking to knock their opponents off the ballot before the May primary.

In the last week of filing, eleventh-hour petition challenges came in from several Democratic campaigns across Philadelphia, Montgomery and Delaware counties.

State Rep. Mary Jo Daley, who is running for her party’s nomination in Montgomery County’s Fourth Congressional District, caught a challenge filed by individuals linked to primary opponent (and House colleague) Rep. Madeleine Dean.

The complaint, filed by campaign lawyer Kevin Greenberg, cites nearly 1,200 allegedly faulty petition signatures. It asserts that some pages feature mere technical violations, while others are purported forgeries. Candidates need at least 1,000 signatures to make it onto the ballot.

Sources close to Daley said she was being targeted because, as the second female House member running in PA-4, she represents the biggest threat to Dean’s campaign. But sources with knowledge of Dean’s challenge alleged that Daley had simply submitted the sloppiest petitions of the three other Democrats vying for a primary nomination – the other candidates being former Congressman Joe Hoeffel and Ceasefire PA director Shira Goodman.

“Integrity of process and accountability matters,” said Dean campaign spokesperson Chris McCann. “Daley's petitions do not appear to meet that standard, including the filing of a petition of signatures collected for Madeleine – and another that were signatures for Joe Hoeffel...There are also many signatures and pages that appear to be signed by a single hand.”

Daley’s camp shot back, stating that her “team has reviewed the challenge and we are confident that the courts will find it completely unsubstantiated.”

Meanwhile, in Philadelphia, supporters of Congressman Brendan Boyle are seeking to knock newcomer Michele Lawrence out of the newly redrawn PA-2. Four individuals filed a challenge on Tuesday, charging a notary retained by the Wells Fargo exec-turned-minister with failing to sign off hundreds of pages of petitions.

Lawrence campaign spokesperson Dan Gross said: “We are confident that we will defeat this challenge, and our campaign is moving full speed ahead to make Michele Lawrence the Democratic nominee to represent Pennsylvania’s 2nd Congressional District.”

Boyle’s campaign did not respond to a request for comment.

Greenberg, who was not involved in the PA-2 challenge, described the accusations as grave, if substantiated.

“The Notary Law is clear that the notary has to sign the document as well as stamp it,” he said. “This is a strong challenge – while there are ways that the defense can make this something for the judge to decide, it is unlikely that a judge would believe that an experienced bank notary would make this kind of mistake over and over again.”

Sparks also flew in other races across Pennsylvania. Sources recently told the Huffington Post that a late challenge in the new Dauphin County seat led Democratic Party favorite Christina Hartman to abruptly drop her bid for Congress altogether. Elsewhere, Teresa Wright picked up a petition challenge in PA-5 – although some observers said they were surprised the unusually crowded Delaware County Democratic primary hadn’t led to more friction. However, Republican Paul Addis, one of just two GOP candidates in that race, also saw his petitions challenged – which could leave opponent Pearl Kim as the sole Republican vying for that seat.