Opposition Leader Blaine Higgs called Thursday for the resignation of Premier Brian Gallant, alleging he covered up his involvement in the property tax assessment controversy.

But within hours, Gallant fired back by holding his own late-day news conference, calling the allegations "unfounded."

Gallant read aloud for reporters internal emails that he contends show his office's intervention was to suggest a media briefing on the new system.

The Gallant government has been trying to fight off criticism since it was learned Service New Brunswick invented renovation amounts for 2,048 homeowners with large assessment increases this past spring. Insiders say that was all part of the chaos created inside Service New Brunswick when the agency switched over to a new assessment system too quickly.

Last week, Gallant was unclear how deeply his office was involved in a decision to accelerate the adoption of a new problem-plagued property assessment system in a single year rather than gradually over three years.

"Was your office or the minister aware of those discussions to make it one year?" Gallant was asked by a reporter on Friday following a raucous question period dominated by the property tax scandal.

"At this point it may be the case, I'm not aware," he had replied.

On Wednesday, however, his office acknowledged it had required Service New Brunswick to submit a detailed rationale for accelerating the switch and gave the final go-ahead to fast track the system.

Premier Brian Gallant called Higgs's allegations 'unfounded' and 'disappointing.' (Jacques Poitras/CBC) "What we know today is that the premier played the role in making this happen," Higgs said during a news conference on Thursday. "It was his decision to fast-track it he needed to take ownership for it.

​"If he had done that a month ago, we might have said 'OK, you messed up and this shouldn't be the way this is done.' But he tried to hide it, deflect it, and blame others … not to take leadership or accountability.

​"So what happens when somebody does that? They need to pay the price and the price for me is that he needs to resign."

Gallant described the move by Higgs as "disappointing," saying the Progressive Conservatives have called for four resignations in the past four weeks.