FILE - Seattle

Seattle skyline and Mt. Rainier, Washington.

City councils and voters are expressing opposition to local governments imposing income taxes after an ongoing legal battle last summer and fall will likely head to the state's highest court.

The Washington Supreme Court is expected to rule on whether the income tax on high-earners approved by the Seattle City Council in 2018 can be implemented, whether the appeal’s court decision allowing a uniform tax across all earners is constitutional, and whether income qualifies as property.

A 90-year-old legal precedent in Seattle, which labels income as property, has helped contribute to other local governments being unsuccessful in levying local income taxes.

Last November, Spokane voters overwhelmingly passed Proposition 2, which asked voters if they supported or opposed banning the city government from imposing a local income tax. A strong majority, 72 percent, answered, “Yes,” effectively prohibiting the City Council from imposing a local income tax.

In neighboring Spokane Valley, the city council unanimously passed a local income tax ban, followed by a similar vote by the Granger City Council.

According to a recent poll conducted by the Seattle-based nonprofit think tank, Washington Policy Center (WPC), the majority of likely voters surveyed, including Republicans, Democrats and Independents, support banning a local income tax.

In Seattle, the split was 49 percent opposed, with 43 percent favoring local income taxes.

“In an era of partisan division, this is one issue that unites Washington voters,” director of WPC’s Center for Government Reform, Jason Mercier, said in a statement. “Washingtonians do not want an income tax and the only people who fail to understand that seem to be some lawmakers in Olympia.”

The statewide poll was conducted among a representative sample of 500 voters, with a margin of error of +/-4 percent.

Washington voters also have rejected income tax proposals 10 consecutive times at the ballot box, the WPC notes, including the defeat of six proposed constitutional amendments designed to increase taxes.

Prior to being elected to his first term in 2012, when asked if he would raise taxes as Washington’s next governor, Jay Inslee repeatedly answered that he would not. His position on the campaign trail was, “I would veto anything that heads in the wrong direction, and the wrong direction is new taxes in the state of Washington.”

Once elected, Inslee proposed large tax increases, including taxing capital gains.

Washington is among seven states that impose no state personal income tax. It is one of six states that levy no corporate income tax.