A Montgomery County Circuit Court judge Friday ruled in favor of County Executive Isiah Leggett in a sharp dispute over collective bargaining, saying Leggett is not required to back a budget he opposes.

The decision, in a case involving the police union, is a legal victory for Leggett (D), who in recent weeks has been called a law breaker by county labor leaders.

The full financial and political ramifications of the ruling remain unclear.

The decision is unlikely to have much affect on this year’s budget process, which is speeding ahead before the County Council. The council has the ultimate authority to make budget decisions, and Leggett’s recommended budget has always been just that, a recommendation.

But the ruling does raise the prospect of significant changes in the way Montgomery and its public employee unions engage in future bargaining over salaries and benefits. Some county officials have long complained that Montgomery’s collective bargaining setup, which often results in deadlocks being decided by unelected arbitrators, is flawed.

Now the value of those rulings has been thrown into question.

Union leaders say they might simply shift their bargaining attention to the council, essentially skipping the county executive as a hostile and unnecessary middleman. Another option would be to seek changes in the county charter forcing Leggett or another county executive to follow an arbitrator’s ruling.

For now, though, Leggett said Friday’s court ruling underscores his commitment to the county’s fiscal health.

“I’m going to fulfill my fiduciary responsibility to the residents of Montgomery County and fight to protect that,” Leggett said. “That’s what we did.”

In March, Leggett disregarded the results of binding arbitration by recommending a $4 billion-plus budget that included cuts to employee benefits and other changes.

A labor arbitrator sided with the police union last week, concluding that Leggett violated the law.

In his ruling Friday, Judge Ronald B. Rubin overturned the decision of the arbitrator, known as a permanent umpire. “The decision of the umpire is reversed,” Rubin said from the bench.

Leggett’s attorneys argued that the county’s charter, essentially considered its constitution, trumps the collective bargaining law.

But an attorney for the police union said the bargaining law required Leggett to endorse the results of collective bargaining, and propose paying for those results in his budget.

“He says, ‘I stand behind this.’ That’s what’s required under this law,” William Chen, an attorney for Montgomery’s Fraternal Order of Police, said Friday.

The judge disagreed.

“The county executive has complied with his obligations under the charter,” Rubin said.

County attorneys e-mailed Friday’s ruling to labor relations administrators who are weighing appeals from the unions that represent Montgomery firefighters and other county employees.

“The collective bargaining law cannot limit the county executive’s responsibility under the charter to recommend an operating budget to the council,” said Edward Lattner, a county attorney.

Walt Bader, a police union official, said Leggett should abide by a signed contract with the police union; Bader said he is considering further legal action.