HALIFAX -- Nova Scotia's premier is promising to review a law that allows members of the legislature to decline appearing in court after his environment minister didn't attend a hearing for a woman accused of assaulting him, causing a judge to drop the charge in the case.

Stephen McNeil said Thursday he was disappointed Andrew Younger didn't show up a day earlier for the trial and will ask the justice minister to review the law.

"I'm disappointed, I believe there should not be two sets of rules for Nova Scotians," he said.

McNeil said he had no idea the law existed until Younger indicated he would use it.

But there were conflicting interpretations of how the law works on Thursday as Younger said repeatedly that he simply followed the law that says sitting members of the legislature cannot be called to testify in civil and criminal matters without being asked to waive the exemption.

"I did not receive a request to waive that. Had I received such a request, I would have had to consider it," he said at a news conference.

"I did not write the law. I followed it."

A spokeswoman for the Public Prosecution Service said Younger chose to assert his parliamentary privilege.

"He did not have to assert his privilege, that was his choice," said Chris Hansen.

Younger spent almost 50 minutes answering reporters' questions about his failure to appear in provincial court Wednesday for the matter involving Tara Gault, who is a former Liberal staff member.

He insisted he was not trying to avoid testifying in the case, which the judge dismissed after denying the prosecution's request for an adjournment to address the issue of the exemption.

"It's just not factual to suggest that I was using some provision as a way to get out of this," he said.

Younger said he was notified of the privilege by his lawyer on Monday. The following day, he said the prosecution indicated they would seek an adjournment and that his wife and lawyer should be in court.

Wayne MacKay, a law professor at Dalhousie University in Halifax, described the law as an "ancient privilege" from Britain that was intended to ensure people could attend the legislature and not have to answer to strategic and frivolous lawsuits.

"In the modern context, it may not be as necessary or sensible as it was when it was first developed," he said.

In Younger's case, MacKay questioned its use.

"It's a rather unusual application of the privilege and it certainly doesn't appear to be the kind of purpose for which it was intended."

Gault pleaded not guilty to the charge stemming from an alleged assault on or about Oct. 22, 2013, the day the Liberal government assumed power after the last provincial election.

Younger refused to discuss the nature of his relationship with Gault, saying only that he had a personal relationship with her that has ended and that he and his wife have moved on.

He would also not reveal anything about the alleged event that resulted in the assault charge.

Both opposition parties said Younger should step down from cabinet, accusing him of abusing the privilege.

"Younger's action sets a very dangerous precedent and sends a message that members of this Liberal government are above the law," interim NDP Leader Maureen MacDonald said in a news release. "It's clear from Mr. Younger's comments ... that he does not have respect for our judicial system. This is unacceptable and the premier needs to sanction him immediately."