HARRISBURG - Amid continued allegations that a community group engaged in widespread voter-registration fraud, Pennsylvania Republican Party leaders asked a state court yesterday to take steps to ensure that only eligible voters cast ballots on Nov. 4.

At issue are an undetermined number of the 140,000 new voter registrations - including 85,000 in Philadelphia - gathered in the state by the activist organization ACORN over the last 18 months.

The suit, filed in Commonwealth Court, calls into question voter applications submitted by ACORN (Association of Community Organizations for Reform Now) in four counties - Allegheny, Dauphin, Delaware and Philadelphia.

Without court intervention, Pennsylvania's 21 electoral votes and the nation's next president "may be determined by illegal ballots," according to the suit, which was filed by seven plaintiffs, including the state party and its chairman, Robert Gleason Jr.

ACORN and top Democrats in the state dismissed the move as a desperate effort by a party that is realizing defeat is just two weeks away.

As has been the case nationally, election officials in Philadelphia have expressed growing concern for weeks about problems with some of ACORN's applications, including registration forms on which names are listed in the same order they appear in a local phone book.

"Exactly how large a problem this is, and how intentional it is, really has yet to be proven," said Zack Stalberg, president of the Committee of Seventy, a nonpartisan election-watchdog group in Philadelphia.

"It sounds to me like the level of rhetoric is a bit too high. At the same time, it is not a non-issue. It's a real issue. It's just that there was an opportunity to fix this. They [the Republicans] let it go to the last minute to get some headlines out of it."

At a news conference in Harrisburg announcing the suit, GOP chairman Gleason charged that "ACORN and other groups like them have perverted the process by manufacturing registrations. They have flooded the county board of elections with fraudulent registrations in the hopes that some would get through. We are concerned that some have."

Sandra Shultz Newman, a former justice of the state Supreme Court who heads the Republican Party's Fair Election Task Force, called the alleged voter fraud an "epidemic that really needs quick antibiotics."

"We can't have a fair election the way things are right now," said Newman, who joined Gleason yesterday.

The suit asks Commonwealth Court to force Pedro Cortés, Pennsylvania's secretary of state, to ensure that the state database used by county elections officials to approve local registration applications is working properly. GOP officials said that they have had reports that the database is often down, creating a backlog of registrations.

The complaint also asks that the court require the state to provide a significantly larger number of provisional ballots at each polling place so that voters whose registrations have not been processed by Election Day can cast ballots. It also asks the court to order ACORN to provide a complete list of all the applications it has obtained and to fund public-service announcements informing first-time voters that they are required to show proof of identity before casting ballots.

Cortés called the suit frivolous and said the allegations are "aimed at doing nothing other than undermining voters' confidence just 18 days before the election."

"The fact that apparently fraudulent registrations have been identified is a testament to the safeguards we have in place to prevent ineligible voters from casting a ballot," said Cortés, adding that the state has not received any complaints about the database system.

ACORN is a nonprofit group that advocates for low-and moderate-income people. Over the last 18 months, it has mounted a massive national drive that has helped 1.3 million new voters to register.

In recent days, some Republicans have been demonizing the group, alleging it has engaged in a conspiracy with Democratic presidential candidate Barack Obama to unduly influence the election. During Wednesday's final presidential debate, Republican presidential candidate John McCain accused ACORN of "maybe perpetrating one of the greatest frauds in voter history in this country, maybe destroying the fabric of democracy."

Philadelphia Board of Election officials last month turned over nearly 1,500 possibly fraudulent registrations - all of them submitted by ACORN - to the U.S. Attorney's Office.

At recent meetings of city election officials, Deputy City Commissioner Fred Voigt said some of those registrations were flagged because voters' signatures seemed to be in the same handwriting. In other cases, registrants' street addresses were found to be vacant lots by city investigators who did site visits.

Some city election officials have been complaining for years about what they regard as shoddy work by ACORN in collecting registrations and managing employees.

"This is what you get when you hire desperate people," Voigt said last week, blaming the recent problems on ACORN's practice of hiring poor people and then requiring them to meet quotas for the number of forms they submit.

Mayor Nutter yesterday downplayed concern over problems in Philadelphia.

"I have no information there is a widespread conspiracy to inappropriately register people to vote, or an intent to submit fraudulent registrations," he said. "Sometimes a mistake is just a mistake - if there was a mistake."

In Delaware County, about 300 voter registrations have been submitted with wrong or inaccurate information, according to the Pennsylvania Republican Party. Voter signatures on some forms appear strikingly similar, while other forms list home addresses of voters who no longer live in those residences.

Republicans claim that, in one instance, a single ACORN worker submitted applications on behalf of several would-be voters who later told county officials they had not filled them out.

Samuel C. Stretton, a veteran election lawyer who has represented Democrats, Republicans and independents in legal fights over voter issues, called ACORN a "pretty respectable organization" and said he did not believe it would intentionally commit fraud.

But he said, "It's always a problem when you do door-to-door registration. . . . Sometimes, people don't tell you the truth."

Moments after the GOP wrapped up its Capitol news conference, ACORN conducted one of its own.

ACORN officials repeated a now-familiar defense of its voter-registration efforts, insisting that it has a sophisticated screening process to weed out questionable applications.

Contact staff writer Mario F. Cattabiani at 717-787-5990 or mcattabiani@phillynews.com.

Inquirer staff writers Kathleen Brady Shea and Marcia Gelbart contributed to this article.