A fiscally conservative group filed a lawsuit Friday challenging the legality of the first legislative pay raise in 20 years, and calling the move by a special pay panel unconstitutional.

"Beyond the unconstitutional delegation of the legislative power, the committee took it upon itself to expand its power well beyond the mandate it had been given," said Executive Director of the Government Justice Center Cameron Macdonald.

Lawmakers will have their pay phased into $130,000 in the coming years, but their outside income will be capped and the legislature must end extra payments to most legislators who hold leadership posts. Cameron Macdonald of the Government Justice Center says the commission itself violates the constitutional provision that the Legislature must set its own pay.

"They had decided to make a policy decision, make their own law, and determine that legislators should be full time," Macdonald said.

The commission itself was created by the Legislature and Governor Andrew Cuomo in the budget this year. State lawmakers like Assemblyman Tom Abinanti say the commission had the power to raise their pay, but it was limited to that.

"This committee did that and then went rogue. They started to make public policy," Abinanti said.

Assembly Speaker Carl Heastie says lawmakers may address what he called flaws in the committee's recommendations, which will have the force of law by the end of the year unless the Legislature overturns the decision.

"There's some technical problems we've identified. Our staff, our lawyers, and members have [equally] raised [problems] that we believe now we're going to have to fix," Heastie said.

Governor Cuomo supported the pay panel's recommendations, but in a radio interview said the criticism from lawmakers does not help to uphold their raise.

"The Assembly has fueled the lawsuit because you have Assembly people who are saying it's unconstitutional," Cuomo said.

The Government Justice Center is trying to block the first phase in of the pay hike from taking effect on January 1, when legislative pay grows to $110,000.