Washington state lawmakers engaged in late-night negotiations as they debated a proposal to impose a tax on millionaires, with the legislative session approaching its final deadline in Olympia.

The proposal, known as the “millionaires’ tax,” would apply a 9.9 percent levy to annual income above one million dollars.

The measure represents a significant policy shift for Washington, which has long been one of the few U.S. states without a personal income tax.

Democratic leaders have advanced the plan as part of a broader effort to reshape the state’s tax system, which relies heavily on sales and property taxes.

Supporters argue that taxing the highest earners would make the system more balanced while generating revenue to support programs for families and children.

The bill has already cleared the state Senate and moved to the House, where lawmakers debated amendments and spending priorities during extended sessions.

Legislators worked overnight to finalize details before the scheduled end of the sixty-day legislative session.

Under the current proposal, the tax would apply only to income exceeding the one-million-dollar threshold, affecting a small share of the state’s households.

Estimates suggest fewer than one percent of Washington residents would pay the tax.

Revenue from the measure is expected to fund expanded tax credits for lower-income households and provide additional support for programs such as early childhood education and child care assistance.

Lawmakers have also discussed linking the revenue to relief measures for small businesses and families.

Governor Bob Ferguson has indicated that he would sign the revised version of the legislation if it reaches his desk, stating that the latest amendments direct more funding toward affordability initiatives and tax relief for working families.

Republican lawmakers have strongly opposed the measure, arguing it could violate constitutional restrictions on income taxes in Washington and warning that future legislatures might expand the tax beyond million-dollar earners.

Critics also say the proposal could discourage investment or prompt wealthy residents to relocate.

The debate underscores the high stakes surrounding tax policy in Washington, where voters have repeatedly rejected statewide income taxes in the past.

Even if the bill becomes law, it is widely expected to face legal challenges and potential ballot initiatives.

As lawmakers worked into the night to resolve remaining disagreements, the outcome of the proposal remained uncertain, highlighting the intense political negotiations that often define the closing hours of Washington’s legislative session.