PROVIDENCE, R.I. (WPRI) — House Speaker Nicholas Mattiello abruptly canceled a controversial audit of the Rhode Island Convention Center on Thursday after the House’s top Republican and the facility’s board both challenged his legal authority to exercise power unilaterally.

At issue is a Dec. 23 letter from Auditor General Dennis Hoyle informing Convention Center executives that the Joint Committee on Legislative Services — or JCLS, which administers the General Assembly’s $46 million annual budget — had directed him to conduct a performance audit of their organization. Target 12 first reported the audit last Wednesday.

The timing immediately raised eyebrows at the State House, because it coincided with a personnel investigation involving Mattiello’s friend James Demers, the Convention Center’s director of security. (Demers and another high-level Convention Center executive have been put on leave.)

The controversy escalated after Target 12 discovered state law says such audits must be requested by a “majority” of the leaders on JCLS, which has five members: Mattiello, House Majority Leader Joe Shekarchi, House Minority Leader Blake Filippi, Senate President Dominick Ruggerio and Senate Minority Leader Dennis Algiere.

The speaker has long exercised unilateral control over JCLS through its executive director, former state Rep. Frank Montanaro Jr., a close Mattiello ally. A majority of the committee’s members — Filippi, Ruggerio and Algiere — told Target 12 they were not consulted about the audit in advance.

That led Filippi to file suit Thursday in Superior Court, arguing he has been “denied the right to vote” on JCLS decisions such as the Convention Center audit. He asks a judge to issue a preliminary injunction to block the audit, as well as a declaratory judgment finding Mattiello and Montanaro “have unlawfully assumed the powers of JCLS.”

The Convention Center Authority’s board — which oversees the Convention Center and Dunkin’ Donuts Center in Providence — took its own action on Thursday morning, voting unanimously not to comply with the audit until it was authorized by JCLS.

“It was reported that the request from the auditor general may be invalid and illegal,” said Vice Chairman George Nee, head of the Rhode Island AFL-CIO.

When asked whether he thought Mattiello’s decision to order the audit was at all related to Demers, Convention Center Board Chairman Bernard Buonanno answered: “Probably.”

Shortly after Filippi sued and the board voted, the speaker’s office released a one-sentence letter from Montanaro to Hoyle: “This letter will serve as notice to your office that the audit of the Rhode Island Convention Center should be immediately cancelled.”

Up to now, Mattiello had defended his right to order the audit. During a taping of WPRI 12’s Newsmakers last Friday, the speaker indicated that while there had been no vote on it by JCLS — which hasn’t met in years — he sees his actions as constituting a majority decision because he is JCLS’s chairman.

In a statement Thursday, Mattiello asserted that Filippi was approached two days ago to sign a letter requesting the Convention Center audit and he initially agreed, but on Wednesday, “when the letter was presented to him for his signature, he became belligerent and refused to sign.”

Mattiello said Filippi “threatened that a lawsuit would be filed and he stated to me that ‘This is political.'” The speaker argued the Republican leader had “turned this into a political stunt.”

Filippi shot back on Twitter: “I’d like to thank the Speaker for acknowledging he didn’t follow the law. No one is above the law — even Speaker Mattiello — and holding leaders to account is no political stunt.”

Filippi’s suit cites the audit as just one example of how Mattiello and his inner circle have, in his view, failed to consult the other members of JCLS on how the Assembly is run. Senate leaders and, at times, House Republicans have lodged similar complaints for years.

“The Senate has long held that the Joint Committee on Legislative Services should meet regularly and vote on matters before us,” Ruggerio and Algiere said in a joint statement Thursday. “Furthermore, we have worked for decades to change the structure of the board. We have regularly sought to bring parity to the committee through legislation.”

John Marion, executive director of good-government group Common Cause Rhode Island, said while he had not yet seen the text of Filippi’s complaint as of Thursday morning, “this suit appears to have merit.”

“The statute plainly requires a majority vote of the JCLS to authorize a performance audit, and that never happened,” Marion said in an email. “There is a simple solution to this problem — a committee meeting and vote. Since the statute doesn’t provide any punishment if the chair violates the law, a lawsuit such as this seems to be one of the only options for another member of the committee.”

Filippi is represented in the case by former R.I. Republican Party Chairman Brandon Bell, an attorney who serves as legal counsel to the state GOP.

“It’s time for those making the laws to stop breaking the laws,” Filippi said in a statement announcing the lawsuit.

Despite Mattiello’s decision to abandon the audit later in the day, Filippi said he has “absolutely no intention of withdrawing the lawsuit.”

“This vigilante audit is just one of thousands of examples of the speaker and Frank Montanaro usurping the JCLS’s statutory duty to manage the General Assembly’s [budget],” he said.

In addition to Mattiello and Montanaro, Filippi’s complaint lists Shekarchi, Ruggerio, Algiere and Hoyle as defendants.

A Superior Court judge called in the involved parties for a closed-door meeting Thursday afternoon. Afterward, Bell criticized the speaker and his control over the JCLS.

“The speaker used the JCLS to punish his foes and reward his allies,” Bell said. “We want to take his deposition. We want to take the depositions of others like Frank Montanaro and others over on the third floor of the State House, and figure out what exactly has been going on in this fiefdom.”

Ted Nesi (tnesi@wpri.com) is WPRI 12’s politics and business editor and a Target 12 investigative reporter. He is a weekly panelist on Newsmakers and hosts Executive Suite. Follow him on Twitter and Facebook

Eli Sherman (esherman@wpri.com) is a Target 12 investigative reporter for WPRI 12. Follow him on Twitter

Walt Buteau (wbuteau@wpri.com) is a Target 12 investigative reporter for WPRI 12 and Fox Providence. Follow him on Twitter and on Facebook.

Tim White contributed to this report.