A Montgomery County Circuit Court judge on Wednesday appeared close to rejecting a petition that put a local police bargaining law to referendum, but he ultimately decided not to make the killing blow.

The judge, Eric M. Johnson, ruled to allow further debate after hearing nearly five hours of legal arguments at a pre-trial hearing Monday for an unusual county lawsuit. The county is suing the county board of elections to block the petition, which challenges a law that curtails expansive police collective bargaining rights. The debate will continue at a trial that starts Monday.

Before the law was passed by the County Council last summer, the police union Fraternal Order of Police could negotiate not only on wages and benefits but also day-to-day duties, such as checking e-mail. As the lawsuit went on, the police union officially joined the elections board as defendants trying to uphold the petition.

The board of elections certified about 35,000 petition signatures in November — about 4,500 more than what are needed to approve the referendum. On Monday, attorneys for the county moved to strike out up to 11,000 of the signatures because they appeared on petition documents with inaccuracies and incomplete information, such as wrong addresses or missing dates.

But lawyers representing the board of elections and the police union argue that state law allows for some discretion. Because of this, parts of the petition should not be invalidated just because of mistakes or omissions.

In his ruling Wednesday, Johnson said some of the inaccuracies made by about 2,400 of the signatures were obviously unacceptable. For instance, four petitioners who were members of the government union, United Food and Commercial Workers Local 1994 Municipal County Government Employee Organization, gave the address of the union office instead of their places of residence.

One of the petitioners, Faye Lapp, gave the county the address of a vacant lot for her place of residence, invalidating all the signatures she collected. In an interview with The Washington Post last year, Lapp described herself as an “old war horse” when it comes to petitions. Still, she said that this was her first time working in Maryland and that other states where she has worked did not ask for her place of residence.

Johnson initially rejected another 6,100 signatures because the petitioners who collected them wrote down incorrect zip codes for their residences. This would have invalidated the entire petition. But shortly after he gave his ruling, he granted a request by the police union’s lawyer to provide evidence next week to prove their validity.

Jonathan Shurberg, an elections law specialist employed by the county to defeat the petition, said at the pre-trial hearing on Monday that he could see appellate judges raising issue with those 6,100 signatures. He said after the hearing that he thinks the trial, whichever side wins, will be appealed to the Court of Appeals, the highest court in the state.

The trial If the petition survives the courts, the law would be put on the November ballot.