A trio of Bucks County residents backed by the county Republican committee say they have evidence linking Democratic Congressman Patrick Murphy's campaign to a scheme to flood the county voter registration office with fraudulent applications for absentee ballots.

In a petition filed Tuesday, county Republicans say the name of Murphy's campaign manager appeared on a Bristol post office box where voters were urged in a series of letters paid for by the state Democratic Committee to send absentee ballot applications.

The county Republicans submitted with the petition a photograph of a note inside the mailbox that said, "Tim Percico and Paul Hampel only pick up mail." Tim Persico is Murphy's campaign manager, although his name is misspelled in the note. Hampel is a volunteer for the Democratic state committee who said he collects mail from the box.

While county and state Democratic officials denied involvement in the letter campaign or refused to discuss it, Persico said Tuesday that the "PA Vote 2010" project that paid for the letters is a partnership between Murphy's campaign and the state Democrats.

Persico said the goal of the project is to help eligible Democratic voters obtain and cast absentee ballots.

He dismissed assertions by Republican critics that the letters were misleadingly worded and noted that the Democratic state committee clearly takes credit for the mailings, which comply with all election laws.

"The only reason the Republican Party is mad is working parents and college kids are sending in an application because they want to vote," Persico said.

Neither Murphy nor a spokeswoman for his campaign returned calls Tuesday.

Bucks County Democratic Party Chairman John Cordisco said the county Democratic organization has no connection to the letters or the fraud alleged in the petition. "If there was voter registration fraud, it was being done outside the Democratic organization," Cordisco said.

In response to the Republican petition, the Bucks County Board of Elections scheduled a hearing 9:30 a.m. Friday at the courthouse to hear evidence of what the Republicans characterize as a coordinated effort to trick voters into improperly applying for absentee ballots and efforts to submit fraudulent applications for absentee ballots.

"While some of these invalid applications have been caught and rejected by the Board of Elections, we believe many other defective and objectionable applications were inadvertently approved by the Board of Elections due to the pervasive nature of the fraud," the petition says.

The petition also asks county election officials to secure all completed absentee ballots at the courthouse in Doylestown until the board of elections can conduct an investigation of the claims.

The petition is signed by Kelly McGinty of Middletown, and Carlo and Lucy Grilletto of Plumstead. Bucks County Republican Party Vice Chairwoman Pat Poprik said party officials and volunteers have gathered evidence in support of the claims put forth in the petition. The signatories are people who have been involved in the Republican Party, she said.

"They're a group of people who are just disgusted with what's been going on," Poprik said. "God bless them, they came forward to do something about it."

The petition is the latest in a series of alarms county and state Republicans have sounded over an influx of questionable absentee ballot applications. Last week, Bucks County District Attorney David Heckler said his office would investigate allegations of fraud leveled by state and county Republican officials.

Voter Registration Director Deena Dean said her staff had rejected more than 600 defective absentee ballot applications as of Friday. Although the voter registration office continued to accept applications until the close of business Tuesday, Dean was unable to provide an updated total.

The petition focused foremost on a series of letters voters in Bucks County began receiving some time after Labor Day. On letterhead of the fictitious Pennsylvania Voter Assistance Office, the mailings warned recipients that their right to participate in the Nov. 2 election might be in jeopardy if they failed to respond.