A Montgomery County Circuit Court judge will decide on Wednesday whether to strike a county petition to put a local police collective bargaining law to referendum.

In an unusual lawsuit, the county has sued its own board of elections to block the petition, which was spearheaded by the police union Fraternal Order of Police and takes aim at a controversial bill approved by the Montgomery County Council last summer.

The law scales back a bargaining process that allowed the union 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 petition signatures — about 4,500 more than what they needed to approve the referendum. On Monday, attorneys for the county argued 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.

According to Jonathan Shurberg, the election law specialist employed by the county to strike down the referendum, a referendum is a “drastic” measure that disrupts government affairs, so strict compliance to state elections laws are required to allow referenda to go forward. Because the law requires petition documents to be fully and accurately completed, the signatures need to be invalidated, he argued Monday.

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 invalidated just because of mistakes and omissions.

Both sides asked for the hearing Monday to get a judgment from the judge, Eric M. Johnson, before the lawsuit goes to trial, which is expected to take place next week. Johnson said at the hearing he will announce on Wednesday his decision on how many signatures, if any, he will discredit.

If he discredits enough, the petition would be rejected. He could also leave the decision to a jury. But it may not matter. Shurberg said he thinks the case will end up at the Court of Appeals, the highest court in the state.

The lawsuit has cost the board of elections $24,636 for legal services provided until April, spokeswoman Margie Roher said in an e-mail. It has cost the county at least $71,780.50 for services provided until March 28, according to county documents obtained by The Washington Post.