WASHINGTON — Supreme Court justices indicated yesterday that they are inclined to uphold a Washington state law restricting unions from using workers’ fees for political activities.

The case involves a few thousand teachers and other education employees who are in the bargaining unit and thus represented by the more than 70,000-member Washington Education Association — but who have chosen not to join the union.

Workers can’t be forced to join or pay for the union’s political activism, the court has ruled, but they can be charged a fee for labor negotiations that affect them.

The fees average $700 a year, union president Charles Hasse said. About 75% of the total goes to the costs of collective bargaining. Of the remaining 25%, just $10 to $25 a year is covered by the state law that the union has challenged.

The narrow issue before the justices is whether, as Washington law prescribed, employees must opt in, or affirmatively consent, to having some of their money used in election campaigns.

The Washington Supreme Court struck down the law, saying the union’s offer to reduce fees for any non-member who registers an objection to the political spending was sufficient.

The state court said the restriction was an impermissible burden on the union’s constitutional rights.

But several justices said yesterday that the law did not strike them as burdensome.

“States have considerable discretion in determining how to protect First Amendment constitutional rights. It seems to me Washington acted quite properly,” Justice Kennedy said, reflecting a view seemingly shared by at least five other justices.

The provision was a small part of a comprehensive campaign finance reform law that Washington voters approved in 1992.

Washington Attorney General Robert McKenna said there’s no reason to think workers who decide not to join the union would want to support its political activities. “They shouldn’t be required to say no twice,” Mr. McKenna said.

Mr. Hasse said after the court session that 300 to 400 workers register an objection each year. “The justices seemed to recognize despite the hyperbole on the other side that this affects just a small group of individuals in Washington state,” Mr. Hasse said.

In practice, the union uses the money only for ballot initiatives, not for candidate elections. Campaign contributions to unionbacked candidates come from a separate political action committee.

John West, representing the union, said workers rights already are protected because they can object to their money being spent on politics.

Union opponents are hoping the court uses this case to bar unions everywhere from spending nonmembers’ fees on politics without their consent.

Justice Alito was the most aggressive questioner in this area. “Why should the First Amendment permit anything other than an opt-in scheme?” Mr. Alito asked.

The Bush administration joined the case in opposition to the union. But Solicitor General Paul Clement said that while the state could enact more restrictions on the union, it was not compelled by the Constitution to do so. Giving workers the ability to register their objection and get their money back is all that the Constitution requires, Mr. Clement said.

The union is the state’s largest teachers union, representing teachers and other employees of public schools and colleges. Less than 5% of employees the union represents choose not to be members, the union said.

The cases are Davenport v. Washington Education Association, 05–1589, and Washington v. Washington Education Association, 05–1657.