The state's highest court has unanimously advised that a controversial plan to freeze the state income tax and prevent it from decreasing can go forward as part of the Legislature's budget debate.

The Supreme Judicial Court has settled a dispute between the House and Senate over whether certain provisions in the House's budget plan alter taxes. The court sided with the Senate, saying in an opinion that by changing taxes, the House's plan legally opened the door for the Senate to proceed
 with the tax freeze.

Under the Massachusetts constitution, tax legislation, commonly known as a "money bills," can only originate in the House.

The decision allows a Senate budget amendment by Sen. Benjamin Downing (D-Pittsfield) to be in play during the Legislature's ongoing budget process. Downing's proposal would freeze the income tax at 5.15 percent and stop automatic decreases to the tax rate currently based on revenue levels.

The House formally requested an opinion from the SJC after the Senate passed its budget in May. In question was whether certain provisions, including one that would delay a tax reporting deadline, classified the House's plan as a "money bill" open to the Senate to add its own tax languages to.

The seven members of the court all agreed that since the provision delaying income reporting deductions "effectively increases the amount of tax revenue that the Commonwealth will realize from certain corporations in fiscal year 2016" the bill is a "money bill."

All seven members of the court signed on to the 27-page non-binding opinion. Leaders of both the House and Senate have said they will abide by the court's opinion.

By handing a win to the Senate, President Stan Rosenberg has scored points in the rivalry between the upper and lower chambers. The Senate's court win could turn out to be a hollow victory ,however, as the tax freeze plan still needs the approval of DeLeo's House before heading to the even more daunting desk of Gov. Charlie Baker.

"I thank the Supreme Judicial Court for delivering the prompt advisory opinion to the questions raised by the House. I appreciate the time and consideration the Court gave to this important matter. Work between members of the Conference Committee will proceed as we reconcile the House and Senate
 budgets," House Speaker Robert DeLeo wrote in a statement.

"We appreciate the prompt and clear answers from the Justices of the Supreme Judicial Court in their response to the request for an advisory opinion.  This opinion allows the budget conference committee to continue to work together and deliver an on time budget to the Governor," Senate President
 Stanley Rosenberg wrote in a statement.

A six-member conference committee is currently working to reconcile the chambers' two budget plans into one to send to Gov. Baker for his approval.