SPRINGFIELD — The state comptroller has long had an obscure role in Illinois government.

But a group of legislators is arguing that without help from the courts, the comptroller could have unlimited power over them.

That’s because if the state’s checkbook chief is legally allowed to delay lawmakers’ salaries, “future [c]omptrollers could refuse any payment until any policy demands are met to the [c]omptroller’s satisfaction,” six legislators argued in a 12-page lawsuit filed in Cook County Circuit Court on Friday against Republican Comptroller Leslie Munger in her final few days in office.

The lawmakers allege the comptroller’s policy is a separation-of-powers violation as well as a violation of a constitutional provision against changing lawmakers’ salaries during their terms. Additionally, it violates multiple state laws on paying state officials each month, the lawmakers argue.

More generally, it threatens the independence of General Assembly members and the will of their constituents, the legislators maintain.

“If the [c]omptroller’s actions are sustained, there will be no limit to the power the [c]omptroller could assert over members of the [l]egislative [b]ranch,” the legislators wrote.

Munger’s office still processed vouchers for the pay each month. But since April she put the warrants for those checks in line with other payments in which the state is behind on, such as payments to social services and businesses.

She said at the time the lawmakers’ money was adding delay to payments toward people who needed it more, and that it could help force a resolution to a months-long budget impasse.

It’s a move that Democratic Comptroller Susana Mendoza, who defeated Munger in a special election last month and was sworn in this morning during a ceremony in Springfield, has promised to maintain.

Mendoza said on Friday in a statement that she would continue “to prioritize the most vulnerable people in our [s]tate and continue the delay in legislators’ pay, unless a court instructs me to do otherwise.”

It’s also reminiscent of the tactic used by former Democratic Gov. Patrick J. Quinn to try to broker a state pension-reform deal more than three years ago.

In 2013, Quinn vetoed lawmakers’ salaries, arguing that as governor he could reduce any line items in the budget he chose to as long as legislators didn’t vote to override his wishes.

But Cook County Associate Judge Neil H. Cohen wrote the move was a violation of Article IV, Section 11 of the Illinois Constitution, which says “changes in the salary of a member (of the legislature) shall not take effect during the term for which he has been elected.”

The lawmakers — Democratic Reps. E. Christopher Welch, of Hillside; Elizabeth Hernandez, of Cicero; Kate Cloonen, of Kankakee; and Sylvana Tabares, Mary Flowers and Sonya Harper, of Chicago — cited that provision and that case in their complaint, as well as the 2004 Illinois Supreme Court decision in Jorgensen v. Blagojevich, in which the high court struck down an attempt by then-Gov. Rod Blagojevich to eliminate pay raises for judges.

“In doing so, the [c]ourt stated as follows: ‘For checks and balances to work properly in protecting individual liberty, each of the three branches of government must be kept free from the control or coercive influence of the other branches,’” the lawmakers’ suit states. “Protecting the [j]udicial or [l]egislative [b]ranches of government from unwarranted intrusion by any executive branch officer is vital to preserving the separation of powers.”

They also claim it’s a violation of Section 1 of the General Assembly Compensation Act, which says lawmakers “shall be paid in 12 equal monthly installments,” and Section 1 of the State Officer Salary Payment Act, which says officials “shall be paid at least once each month.”

The salaries are usually paid on the last day of each month, and amount to about $1.3 million per month or $15.6 million annually.

According to the two-count complaint, the last month for which lawmakers were reimbursed was May. The lawsuit asks for a judge to order the office to immediately compensate them for the months of pay they’ve missed.

Michael J. Kasper, a partner at Fletcher, O’Brien, Kasper & Nottage P.C., represents the lawmakers. He declined to comment this morning on the litigation.

A spokeswoman for the attorney general’s office could not be reached to confirm whether the office will represent the comptroller’s office in the lawsuit.

Republican Gov. Bruce Rauner, who has been locked in a battle over the budget with Democrats in the legislature for more than a year, today called the lawmakers’ pay suit “frivolous” and “a stunning reminder of why we need change in Springfield.”

“Only in Illinois would politicians who have failed to pass a balanced budget and reforms put their own personal gain before taxpayers and critical human services,” Rauner said in a statement, adding that he does not take a paycheck for his gubernatorial role.

The Democratic legislators who filed the suit last week said in a joint statement that the pay delay was a “thinly veiled” attempt to get them to acquiesce to Rauner’s demands, and that neither he nor Munger, who is also a businesswoman, needs their government salaries because they have “multimillion-dollar side incomes.”