OLYMPIA, Wash. — The Washington Senate narrowly approved a new state estate tax on the wealthy late last night.

The tax would apply to estates of $1.5 million or more this year and those of $2 million or more beginning next year. It would raise an estimated $135 million over the next two years, affecting about 250 estates.

The measure was the first big revenue bill to pass either chamber this year, and cleared the Senate by a vote of 25-21. Conservative Democrat Tim Sheldon of Potlatch joined Republicans in opposition.

The plan now heads to the House for swift approval. Gov. Christine Gregoire was the original proponent and is expected to sign the measure.

The new state tax is a narrower version of one that the state Supreme Court struck down earlier this year, leaving a budget hole of more than $500 million, counting the revenue loss and the requirement for rebates.

Majority Democrats said the estate tax revenue will be earmarked for an education trust fund that helps finance a voter-approved class-size reduction program, Initiative 728, and efforts to boost college enrollment.

Republicans called it a "death tax" that could cause wealthy elderly residents to flee to other states. The education improvements could be handled within existing revenue, said Sen. Joseph Zarelli, R-Ridgefield, the chief GOP budget negotiator.