SETTING THE STAGE for another confrontation with the Baker administration, leaders of the Transportation Committee on Wednesday scheduled a hearing next week in their ongoing probe of the massive procedural failure connected to a fatal crash in New Hampshire last month.

Unless something has changed since Monday, that schedule doesn’t mesh with Transportation Secretary Stephanie Pollack’s insistence on keeping certain information about dysfunction at the Registry of Motor Vehicle’s out of the public view until an investigation commissioned by her office is complete.

In their letter, the committee’s co-chairs, Rep. William Straus of Mattapoisett and Sen. Joseph Boncore of Winthrop, requested the appearance of witnesses who were no-shows Monday as well as documents that Pollack has yet to send them. The letter, which is posted on the committee’s website, says the lawmakers expect Pollack and the other witnesses to testify “without exception or qualification.”

Pollack previously said she wanted to temporarily shield some information to preserve the integrity of an ongoing investigation by the audit firm Grant Thornton. The firm was hired to look into the failure of the Massachusetts Registry of Motor Vehicles to act on infraction notices sent from out-of-state counterparts. Pollack said officials discovered the lapse after looking into the circumstances surrounding Volodymyr Zhukovskyy, a commercial truck driver whose license should have been suspended before he allegedly killed seven motorcyclists in New Hampshire’s White Mountains last month.

The audit firm began its work the week of July 8 and its final recommendation is due within 60 days, Pollack previously told lawmakers. She offered to present a 30-day report and 60-day report to the committee, but the July 30 noon session that Straus and Boncore scheduled on Wednesday would fall within 30 days of Grant Thornton’s start date.

The letter was sent two days after lawmakers abruptly recessed a Registry of Motor Vehicles oversight hearing after expressing frustration that multiple witnesses – including two current state employees – had failed to show up as requested, and that Pollack was withholding documents and information.

On Wednesday, the committee also requested the appearance of one additional witness, Brie-Anne Dwyer, who is a project manager in MassDOT’s audit operations, according to payroll records. The letter doesn’t say what light the committee chairmen think Dwyer could shed on their investigation.

In a statement after this story was originally published, MassDOT said it would “continue to cooperate with the committee as fully as possible,” and suggested current employees and vendors would be there.

“Current RMV employees and vendors invited by the committee are scheduled to testify, additional requested documents are being provided and, when completed, the Administration will share the findings of the independent forensic review currently underway,” said Jacquelyn Goddard, MassDOT spokesperson.

In language that could read as legal boilerplate or an escalation of the lawmakers’ dispute with Republican Gov. Charlie Baker’s administration, Straus and Boncore underscored their directive for state officials to preserve all the requested records and warned of what might happen if the administration fails to do that.

“We emphasize that records, documents or data from any source (state owned or personal) are an important source of evidence in the Committee’s investigation. You must take every reasonable step necessary to preserve this information until further notice,” Wednesday’s letter said. “The failure to do so could be a violation of state law and could also be deemed contempt of the General Court.”

On Monday, hours after the committee dismissed Pollack and Acting Registrar Jamey Tesler, House Speaker Robert DeLeo issued a statement of support for lawmakers’ inquiry.

“I call upon the Administration and MassDOT to participate in the Committee’s fact-finding process without exception or qualification,” DeLelo said Monday. “The Legislature will not be thwarted in the discharge of its oversight responsibilities. The citizens of the Commonwealth deserve nothing less.”

Monday’s curtailed hearing occurred while Baker was out of state for a meeting of the Republican Governors Association, but he was back in town on Wednesday.

In their Wednesday missive, the chairmen also said they will extend until Monday at 1 p.m. the deadline for MassDOT to produce “all the remaining records, documents and data previously requested by the Committee.”

In a letter to lawmakers dated July 19, Pollack had explained that some of the documents requested would be provided immediately, others would need to be assembled and reviewed for privacy and other considerations, and still others “cannot be produced until the completion of the forensic review.”