CHICAGO (CBS) — Republicans on a committee investigating possible disciplinary action against Illinois House Speaker Michael Madigan want to use the panel’s subpoena power to force him to testify about the ComEd bribery scandal, after he refused to appear voluntarily.

But the Democratic lawmaker leading the panel said the Republicans “are solely interested in headlines, half-truths, and distractions to prop up their dimming political prospects.”

Illinois State Reps. Tom Demmer (R-Dixon), Deanne Mazzochi (R-Elmhurst), and Grant Wehrli (R-Naperville) said Thursday they have drafted subpoenas to compel Madigan and other potential witnesses they want to question to appear before the Special Investigating Committee (SIC).

“Speaker Madigan and others named in the Deferred Prosecution Agreement (DPA) between Commonwealth Edison and the US Attorney of Northern Illinois have relevant and useful information that is vital to the SIC’s ability to do it’s job properly,” Wehrli said in a statement. “Only by questioning these witnesses will we be able to build out a broader picture of what exactly transpired with regard to ComEd’s admission that they engaged in a bribery scheme to gain favor with Mike Madigan. It’s through getting people to testify under oath that we obtain a full and complete record.”

Earlier this year, federal prosecutors accused ComEd of a yearslong bribery scheme that sought to curry Madigan’s favor in advancing legislation relaxing state regulation of ComEd’s rates by directing $1.3 million in payments to the speaker’s associates. ComEd acknowledged it stood to benefit by more than $150 million from that legislation.

ComEd has entered into a deferred prosecution agreement with the feds, and has agreed to pay a $200 million fine, enact a number of reforms, and cooperate with investigators in exchange for prosecutors dropping charges in 2023 if ComEd lives up to its obligations.

Madigan has not been charged with a crime, and has denied any wrongdoing.

“Speaker Madigan needs to come forward and testify,” Wehrli said.

In order to subpoena Madigan, the three Republicans on the six-member bipartisan Special Investigating Committee would need the support of at least one Democrat, which appears unlikely, based on a statement from the committee’s chairman, Rep. Emanuel “Chris” Welch (D-Hillside).

“The questions of whether the Special Investigating Committee should issue subpoenas, what any subpoenas should seek, and who should receive them are extremely consequential decisions, and could set precedents that affect the work of this Legislature for decades to come. We need to fully understand what these decisions mean before we act,” Welch said in a statement.

Welch has repeatedly accused Republicans on the panel of using the hearings “as a stage for political theater.”

“The Committee will not rush into actions that could interfere with the work of federal investigators – regardless of the political considerations of some members seeking to use this Committee to bolster their own difficult re-election campaigns,” Welch said.

The Republicans on the committee had argued for subpoenas at the committee’s meeting on Tuesday, after the panel questioned ComEd executive vice president of compliance and audit David Glockner about the deferred prosecution agreement.

Republicans had also sought voluntary testimony from Madigan and several former ComEd lobbyists and executives, but none of the other people on the GOP witness list agreed to appear.

Welch ruled Republicans’ request for subpoenas out of order on Tuesday, calling it premature to discuss subpoenas the panel hasn’t seen or discussed. On Thursday, Welch said the Republicans on the committee sent him drafts of subpoenas only minutes before holding a press conference to announce them.

“Once again, Republican members have shown that they are not interested in cooperation, they are not interested in a serious process befitting the rules they invoked, and frankly they are not interested in the truth. They are solely interested in headlines, half-truths, and distractions to prop up their dimming political prospects,” Welch said.

Wehrli said it’s necessary for Madigan to come forward and testify in order for the committee to do its work.

“Our investigating committee has a specific and important charge, and our process is separate from the ongoing federal investigation into political corruption in Illinois,” said Wehrli. “Our committee’s work is about protecting the integrity of the Illinois House of Representatives, and about holding our colleagues accountable for their actions.”

The committee is looking into possible disciplinary charges against Madigan, after House Republican Leader Jim Durkin and two other Republicans filed a petition accusing him of “conduct unbecoming to a legislator.”

If a majority of the Special Investigating Committee – comprised of three Democrats and three Republicans – determines there is probable cause to file disciplinary charges against Madigan, a separate 12-member disciplinary committee would be formed to vote on each possible charge.

If the disciplinary panel approves any charges, the full House would then vote on any possible disciplinary action. A two-thirds majority vote would be required to sanction Madigan. That would mean, at any point in the process, at least some Democrats would have to support disciplinary charges against Madigan for him to be punished.