A Montgomery County judge zeroed in Friday on the fundamental disconnect driving a legal dispute over collective-bargaining laws and said he plans to issue a ruling Monday morning in the lawsuit filed against the county by a public employees union.

“You have, it seems to me, a conflict,” Circuit Court Judge Robert A. Greenberg said. “You have collective bargaining, but the county executive can basically do what he wants.”

The Municipal and County Government Employees Organization sued the county last month, saying County Executive Isiah Leggett (D) broke the county’s collective-bargaining law when he recommended a budget that failed to include the results of binding arbitration. The union represents a wide range of employees, among them bus drivers and health workers.

Leggett said that he supports collective bargaining but that the county’s charter, which is essentially its constitution, trumps the bargaining law and gives him the authority to propose a budget that includes painful but necessary cuts to improve the county’s fiscal health.

The judge has a range of options. One possibility is he will say that the union was premature in taking the matter to court and that it must first go to a labor-relations administrator, who is part of the bargaining process. That route was taken by the county’s police and firefighter unions.

Greenberg also could rule in ways that would have a far-reaching impact on governance and labor relations in the liberal-leaning county. He could order Leggett to rewrite his proposed $4.35 billion budget, as the union has called for, or he could endorse Leggett’s position that he has “virtually unchecked” power to offer whatever budget he believes is responsible.

Some county officials said privately that the government employees union has taken a risk by pushing the issue into the courts and trying to eliminate any legal ambiguity. The county’s labor laws have worked to the advantage of such unions, with arbitrators in the quasi-judicial system often ruling on the side of public employees. This year, all three arbitrators ruled in favor of the unions.

But Carey R. Butsavage, an attorney for the union suing the county, said the union refuses to be left with the status quo, in which Leggett asserts he can essentially do what he pleases under the collective-bargaining law.

“We’re going to continue on and find out what this law means,” Butsavage said after Friday’s hearing.

He praised Greenberg’s fairness but said union leaders would persist even if Greenberg rules against them.

“If it takes going to the Court of Appeals, and if it takes going to the Supreme Court, we’re going to do that,” Butsavage said.

An attorney for the county, Edward B. Lattner, said Leggett has the discretion to make budget decisions for the public good.

“The public interest is not served when that discretion is delegated to a labor arbitrator who is not accountable to the residents served by the county’s budget,” the county said in legal filings.

Moreover, seeking “an injunction to compel the County Executive to espouse a view that he does not hold . . . is repugnant to the principles protected under the First Amendment of the U.S. Constitution,” according to county filings.

Although Leggett sent his recommended budget to the County Council last month, the union asked the court to force him to resend it to the council without proposed cuts in health care and other areas, which county officials say could cost some employees thousands of dollars a year. The union’s money-saving proposals would be included instead. The council has the final say on setting spending.

Union leaders said Friday that if arbitration is found by the courts to not be binding, they would seek new ways to protect their interests.

One would be ignoring Leggett altogether when it comes to hashing out salaries, benefits and other contract provisions.

“We’ll start directly negotiating with the County Council,” said Gino Renne, the head of the government employees union. He said the union spent heavily to present a comprehensive case before an arbitrator, just to have its win thrown out.

“Why bother going through the exercise?” Butsavage asked.

“We’ll just take our chances with the council,” Renne said.

If union leaders lose in the courts, they will appeal to the council for changes in the law, Renne said.

“Let’s amend the law and get the right to strike,” he aid. “Either we have binding arbitration, or we don’t. If we don’t, we ought to have the right to strike.”