Gov. Mark Dayton vowed Tuesday not to cooperate with a legislative panel that wants to question top officials in his administration about technical problems that marred the Oct. 1 launch of MNsure, the state’s health insurance exchange.

Republican members of the MNsure Legislative Oversight Committee want to interview several key officials involved in MNsure’s rollout, including state Human Services Commissioner Lucinda Jesson. Their request came in response to a Star Tribune report published Sunday that revealed how problems with the website were known months before the launch and that Dayton was warned about serious shortcomings 12 days before its public debut.

The Republicans said the report raised new questions about “management failures at MNsure before its launch.”

MNsure did not address most of the major problems identified by outside auditors by Oct. 1, according to the Star Tribune, and critical system tests either came too late or had to be reduced.

State Sen. Tony Lourey, the DFL co-chair of the oversight panel, said Republicans have “legitimate questions” that deserve to be answered.

“We do need to answer for how the rollout occurred, and we certainly will,” Lourey said. “I am totally open to that.”

During a news conference Tuesday, Dayton said Republicans are “making a mockery of the word oversight” and engaging in a “propaganda campaign” aimed at destroying MNsure.

“It is really irresponsible,” Dayton said. “The fact that they can pretend this is part of the oversight process is just ludicrous. They want to trash MNsure. … They want MNsure to fail.”

MNsure has enrolled more than 175,000 people, well above a conservative target of 135,000 set in mid-October. But the agency continues to struggle with website glitches and crashes.

Jesson was the only MNsure board member to receive regular briefings about widespread technical problems in the months leading up to MNsure’s debut. She also acknowledged that she signed off on the decision to launch the website just days after an outside auditor determined there were 270 software problems in the system. The number of defects rose to 394 by Oct. 9, state records show.

Initially, it appeared that Jesson would be answering questions at Wednesday’s oversight hearing. She was listed as a witness on an updated committee agenda, and a senior adviser to Dayton said in a Tuesday statement that the decision on whether to answer the summons was left to Jesson. But Dayton advisers later said that Jesson was asked to skip the meeting for the reasons Dayton articulated at his news conference.

“That is a really bad idea,” said Sen. Sean Nienow, one of the four Republicans who asked for Jesson’s appearance. “If we could just come to the table and recognize that challenging questions aren’t a partisan attack, it is just part of our oversight responsibility, we could all do a better job for Minnesota.”

Nienow and the other Republicans on the panel denied that they are engaging in a partisan witch hunt.

“It is not a campaign to destroy MNsure. It is to understand what mistakes were made and could it have been done better,” said Sen. Michelle Benson, R-Ham Lake. “It is important for us not to repeat the mistakes of last summer. This has been a really expensive learning process.”

At Tuesday’s news conference, Dayton also addressed allegations that he misled people by saying he was unaware of MNsure’s technical problems until sometime in November.

“I misspoke,” Dayton said. “There was a meeting on Sept. 19 where I learned for the first time there were operational problems that called into question whether MNsure could start on Oct. 1.”

Republicans said the governor’s reluctance to publicly debate MNsure’s problems reflect a pattern of obfuscation by MNsure managers and administration officials.

“Nobody really wants to take the blame for this one,” said Rep. Tara Mack, R-Apple Valley. “A group of people knew we had a broken website and they made a collective decision to let it roll out anyway and let Minnesota be the victim and waste time.”

Republicans wanted a chance to question MNsure’s former chief executive, April Todd-Malmlov, who repeatedly downplayed concerns about technical glitches at a time when she was getting internal and external reports showing widespread performance problems.

Legislative Auditor James Nobles, who is conducting a review of MNsure, said Todd-Malmlov has so far declined to discuss her stewardship of the agency. Nobles said he will take the unusual step of issuing a subpoena and using the courts to compel her testimony if she does not come in voluntarily for an interview.

“We think there are a lot of questions that need to be answered in a thorough and objective way,” Nobles said. “We want to hear her perspective. … She was at center stage, so to speak, and knows more than probably anybody.”

Todd-Malmlov, who resigned from MNsure in December after she refused to accept a demotion, did not respond to a request for comment.