OLYMPIA - While state lawmakers struggle to close a $1.5 billion budget shortfall, they're also considering a constitutional amendment that would help prevent such gaps in the future.

The state Senate has approved a proposed amendment that would require the Legislature to pass a balanced budget - and prohibit spending or other actions that would create a future shortfall.

Constitutional amendments require a two-thirds vote in the Senate and House, and a simple-majority approval by voters. Senate Joint Resolution 8222 now goes to the House for consideration. It's not clear how the measure will fare there.

If approved by the House, the amendment would go on the November ballot.

"If we're going to come out of the session saying we really passed substantial reforms, having a balanced-budget amendment that goes before voters will be the strongest thing we can say that we're serious about getting our financial house in order," said Sen. Jim Kastama, D-Puyallup, the prime sponsor of the measure.