Attorneys for Montgomery County will make their first court appearance Friday in an unusual lawsuit that could prevent a controversial police labor law from appearing on November’s ballot.

The case pits the county executive and council against the county Board of Elections.

The law, passed unanimously by the County Council last summer, scales back a bargaining process that allowed the Fraternal Order of Police to negotiate not only wages and benefits but also day-to-day duties, such as checking e-mail.

In November, county elections officials certified about 35,000 signatures on a petition to put the law to a referendum. But county officials say that potentially thousands of signatures were missing dates, first initials or middle names and that the Board of Elections erred. They have asked the courts to rule that the petition should not have been approved.

The lawsuit comes as community activists across Maryland are embracing the referendum process to try to repeal controversial legislation. A law that would give undocumented immigrants in Maryland breaks on in-state college tuition will be on the November ballot, and another legalizing same-sex marriage, signed Thursday by Gov. Martin O’Malley (D), is likely to be put to voters as well.

Just a couple of years ago, opponents of a Montgomery law instituting ambulance fees petitioned to a referendum. County elections officials were sued because they rejected the petition, but the Maryland courts ultimately approved it, allowing the referendum to go forward. The law was repealed.

In a closed session last month, the County Council gave its blessing for the litigation challenging the labor-law petition to continue. According to legal documents filed by the county, union workers and other signature gatherers misrepresented the law to voters and improperly filed petition documents.

During the closed session, the county’s attorneys did not discuss any alleged acts of deception, according to three people who attended the meeting but were not allowed to speak publicly about the matter. Rather, the attorneys said they had inspected more than a quarter of the signatures and found discrepancies among them. Those discrepancies included missing dates and missing first or middle names, according to one of the attendees.

The County Council is going ahead with its challenge to the petition, the person said, “because our attorneys think we’re in a good place.” The attendee added that the attorneys are likely to address allegations of deception at a later meeting.

But in interviews, signature gatherers dispute the county's account, saying they performed a professionally run campaign throughout the county last fall.

“That was one of the cleanest, most carefully presented petitions from everyone involved that I have ever been on,” said Faye Lapp, 54, a self-described “old war horse” in petition campaigns. “There was no room for error.”

Council member George L. Leventhal (D-At Large) said he raised concerns during the closed session. “I think it’s unwise to purge signatures on technicalities,” he said.

Leventhal was the sole legislator who voted against the lawsuit when the County Council first discussed it in November. In closed session, council members Phil Andrews (D-Gaithersburg-Rockville) and Hans Riemer (D-At Large) joined Leventhal in dissent, citing similar concerns, according to Leventhal and other attendees.

In an interview, Riemer confirmed his opposition but declined to comment further. Andrews declined to comment on the closed session but said that the November vote simply gave county attorneys permission to review the petitions, not definitively pursue a lawsuit.

Police union secretary Jane Milne said in a statement that county police officers “followed the law in order to place the issue before the voters.” County Attorney Marc Hansen declined to comment on the lawsuit for this article. Jonathan S. Shurberg, a local elections law specialist working on the case for the county, has not responded to requests for comments since the petition was announced in November.

Locked in a warehouse in Gaithersburg, thousands of pages of signatures make up the police union’s petition. Union officials paid petitioning firm PCI Consultants to help them. Signature gatherers drawn from across the country descended in the fall on parking lots, supermarkets and malls throughout Montgomery County.

Some workers said they thought the county was wrong to strike down effects bargaining. “What the County Council was trying to do was straight out of Scott Walker’s playbook,” signature gatherer Timothy C. McArdle, 52, said, referring to Wisconsin’s Republican governor, who last year rolled back most state employees’ collective-bargaining rights.

But McArdle and other signature gatherers said they didn’t misrepresent the issue to voters. The Washington Post tried to reach 18 of the signature gatherers, but only a handful responded. They described their employer, PCI, as a professionally run operation, with troupes of people going from state to state, city to city, to work on various hot-button issues — stem-cell research, medical marijuana, living wages — for a little bit of cash.

Foster D. Turner of Kalamazoo, Mich., took a 24-hour train ride to Montgomery to meet his colleagues, who had already been in a hotel in Frederick County for about six weeks. Every day, about 15 of them would stay outside from about 9 in the morning to 8 at night, Turner said.

He said the workers were paid $1 per signature and would make about $100 each day. “A lot of people didn’t want to sign it,” he added, “because they didn’t like the unions.”

Lapp, who also lives in Kalamazoo, said she was surprised at first that so many people had that “knee-jerk reaction.” She said the anti-union sentiment was the main reason people didn’t sign, and about one in five people she approached would sign.

Turner said that every signature gatherer had his or her own pitch. “Whatever works for you, I guess,” he said. “Whatever works, however you say it, and then they sign it.”

Lapp said she tried to narrow the issue so residents knew general collective-bargaining rights weren’t affected. “Being too broad is kind of unethical,” she said. “You try to say this is a non-monetary right of the unions. You try to insert words that differentiate a specific issue from a broad issue. This is not union rights in general but non-monetary bargaining, or effects bargaining.”

County officials say the pitches went too far. Council member Nancy Navarro (D-Eastern County) said she was approached by a signature gatherer in the fall at the Giant Food on New Hampshire Avenue in Colesville. The signature gatherer’s pitch, according to Navarro, was “This council has rolled back collective bargaining rights, and Montgomery County is becoming another Wisconsin.”

Council member Nancy Floreen (D-At Large), who was never approached by signature gatherers, said that “advocates . . . rarely are complete or fully accurate in their advocacy.”

But Leventhal said that when the petition gatherers approached him, they used statements that were neither “strictly true” nor “strictly false.” He added that he stands by his decision to repeal effects bargaining.