Associated Press

SEATTLE (AP) _ The Washington Supreme Court is scheduled to hear arguments Thursday on whether a voter-approved initiative to raise the minimum wage in SeaTac to $15 an hour should apply to workers at the airport.

Businesses and the Port of Seattle argue that the airport is run according to state and federal law, not local ordinances.

Labor groups that sponsored the initiative approved by SeaTac voters in November say one of their aims was to improve working conditions at the airport.

The court hearing is the latest development in the debate over the minimum wage in Washington, which already has the nation’s highest state minimum wage at $9.32 an hour. The Seattle City Council voted early this month to gradually raise the minimum wage in Washington’s largest city to $15 an hour. That decision is also being challenged in court.

In the case of the SeaTac ordinance, King County Superior Court Judge Andrea Darvas ruled at the end of December that it does not apply to the airport because it is controlled by the Port of Seattle, not the city of SeaTac.

Darvas said the state Legislature has given municipalities like the Port of Seattle “exclusive jurisdiction” over their operations. She ruled the law does apply to about 1,600 hotel and parking lot workers in SeaTac, but not to employees and contractors at the airport.

The Supreme Court’s decision in this case could have far-reaching implications for other Washington municipalities considering minimum-wage increases and other port authorities in the state.

Washington Attorney General Bob Ferguson and Solicitor General Noah Guzzo Purcell ask in a brief to the court for clarification concerning the port’s authority over wages paid by other employers at the airport. They call on the court to reverse the lower court’s decision and declare the SeaTac wage ordinance applicable to the airport.

Dmitri Iglitzin, lawyer for the SeaTac Committee for Good Jobs, expects the issue of the port’s authority, which originates in a 1948 state law, to be the centerpiece of the legal argument on Thursday. “We are cautiously optimistic the Supreme Court is going to uphold the power of the city of SeaTac to enact worker protection regulations” that affect employees both inside and outside of the airport, Iglitzin said.

Even if the Supreme Court doesn’t agree with the city of SeaTac and his group, Igitzin expects the court will uphold the rest of the minimum wage law, which he said would be a victory for some and continue to inspire other municipalities to act.

Many others have weighed in on this issue through a flurry of briefs filed with the Supreme Court, covering a variety of legal issues.

A Washington, D.C.-based airline industry group called Airlines for America, for example, argues in its brief that federal airline, railroad and employment regulations pre-empt the SeaTac city ordinance. Lawyers for the group say the ordinance interferes with the airlines’ ability to set prices and bargain with employee unions.

Other issues raised in the briefs include perceived problems with the initiative process, questions about the way the case was heard at the trial court, and queries about whether the original ordinance was written properly and signatures counted correctly.

The Port of Seattle gave a nod to the minimum-wage issue on Tuesday by proposing its own new rules on wages, paid time off and career development.

“We’ve chosen to lead on this issue and not follow,” port Commissioner Stephanie Bowman said during a meeting Tuesday. “It would have been easy to punt and let the courts decide.”

The port commission plans to vote next week on a proposal that would raise the minimum wage for workers who require a security badge to do their jobs to $11.22 an hour in January 2015 and $13 an hour in January 2017. The port estimates more than 3,000 people would get a raise under the proposal, which would apply to jobs like baggage handlers but not restaurant workers.