The Montana Supreme Court has ruled that a legislative referendum calling for income-tax credits when there is surplus state revenue is unconstitutional.

Friday's 4-3 decision upholds a district judge's ruling that the referendum cannot appear on the November ballot.

The referendum would have required the state Revenue Department to issue income-tax credits if the state general fund balance exceeds the Legislature's projection by a certain percentage and dollar amount.

District Judge Jeffrey Sherlock ruled in June that the referendum is an unconstitutional delegation of power by the Legislature.

The Supreme Court upheld that ruling taking up the expedited appeal. The decision was signed by Chief Justice Mike McGrath, who wrote that a full opinion will follow in due course.