The state Supreme Court on Wednesday agreed to take up the case directly.
The new group was announced by the Wisconsin Elections Commission last week.
“State agencies comprised of political appointees and unelected staff do not have the authority to invent or amend policy contrary to state law," WILL president Rick Esenberg said.
The proposed constitutional amendment comes after Democratic Gov. Tony Evers used his veto power to increase K-12 spending in the current state budget.
Republicans in the state Assembly last week passed new rules to allow disabled legislators call-in to meetings and let lawmakers take unlimited veto override votes.
Lawmakers Thursday also approved resolutions supporting the Air Force's plan to locate F-35 jets at Truax Field and honor retired Madison Police Chief Mike Koval.
The rule changes passed over opposition from Democrats, including paralyzed Rep. Jimmy Anderson, who argued the language was a continuation of the December lame-duck laws that limited the incoming governor's powers.
An informal survey by the Cap Times and review of other records from Madison City Council members, Dane County Board supervisors, school board officials and state lawmakers whose districts include Dane County showed most either have not taken a position or did return requests for comment.
Pollsters and strategists from both sides of the aisle agreed during a Wednesday summit in Madison that Democrats continue to have the advantage on health care this cycle.
The resolution is one of a series of measures state representatives are poised to consider Thursday when the Assembly convenes for its first fall floor period.