Mattiello canceled his request in a letter to Auditor General Dennis Hoyle.

In the Superior Court lawsuit filed by GOP lawyer Brandon Bell, Filippi states that a majority vote by the five-member Joint Committee on Legislative Services was required to trigger an audit.

With Mattiello scrapping his request for the audit, Bell said he plans to pursue discovery in the lawsuit "to push him on all JCLS actions past and future." Bell said the request for an injunction remains in place, but that it may be moot.

The suit was filed against Mattiello, the other members of JCLS (Senate President Dominick Ruggerio, House Majority Leader Joe Shekarchi, Senate Minority Leader Dennis Algere), as well as Auditor General Dennis Hoyle and JCLS Executive Director Frank Montanaro.

Mattiello has acknowledged asking Hoyle to pursue the audit of the Convention Center. During an interview on Newsmakers on WPRI-TV this past weekend, Mattiello asserted that he, as the chairman of JCLS, had the authority to request such an audit.

As WPRI reported, the audit request occurred at around the time when a friend of the speaker who works at the Convention Center Authority, Jim Demers, was engulfed in a personnel issue.

In a statement, Mattiello fired back at Filippi.

“On Tuesday, Minority Leader Filippi had indicated that he wanted an audit and believed one was appropriate," Mattiello said. "He stated he would sign a letter requesting that an audit be conducted at the Convention Center. On Wednesday, when the letter was presented to him for his signature, he became belligerent and refused to sign the letter. He threatened that a lawsuit would be filed and he stated to me that ‘this is political.’ "

Mattiello, who has been speaker since 2014, said he now believes regular audits of Rhode Island's quasi-public agencies are necessary.

Filippi's predecessor as House GOP leader, Patricia Morgan, had called for years for an audit of the Convention Center.

The board of the Convention Center Authority voted unanimously Thursday against pursuing the audit, according to Executive Director James McCarvill.

JCLS, the hiring and spending arm of the legislature, is effectively controlled by the speaker since the House has three members on the committee, while the Senate has only two.

The issue continued playing out Thursday afternoon, as the House GOP caucus vowed to press ahead with the lawsuit. Filippi told reporters the case could reveal other instances of wrongdoing involving JCLS.

“So our ultimate goal is to get an order, a preliminary and permanent injunction, against the speaker – whoever that might be, the office of speaker – who sits as the chairman of JCLS – an injunction preventing the future exercise of the sole statutory responsibilities of JCLS,” Filipp said.

Mattiello declined to specify his precise reason for seeking the audit, but said it was justified by information he received.

The speaker accused Filippi of politicizing the issue rather than formally requesting a meeting of JCLS. (No one is sure when the committee last met.)

“The leader’s action is putting politics above substance and above what’s in the best interest of taxpayers," Mattiello said. "I stand for transparency.”

In a joint statement earlier Thursday, Senate President Dominick Ruggerio, a Democrat, and GOP Leader Dennis Algiere, issued a joint statement:

“The Senate has long held that the Joint Committee on Legislative Services should meet regularly and vote on matters before us," they said. "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.”

The lawsuit filed on Filippi’s behalf charges that Mattiello “has taken actions and directed others to take actions without authority, most recently the order purportedly by JCLS, without any vote, to audit the Rhode Island Convention Center Authority.”

The suit said Mattiello’s action is hurting Filippi since he “has been denied the right to vote on such matters and has no adequate remedy at law to rectify the abuse of power by Defendant Mattiello and other Defendants named herein.”

The lawsuit is noteworthy given the cordial relationship between Filippi and Mattiello. It could also be an important test case for JCLS, a little-known but powerful organization.

The story has been updated.