Nova Scotia Premier Stephen McNeil's chief of staff learned about allegations of drunk driving against a Liberal MLA last May, but did not inform her boss that she knew until Tuesday.

Chester-St. Margaret's MLA Hugh MacKay, who is now sitting as an Independent, was charged earlier this month in relation to allegations dating back to November 2018. He pleaded guilty in a separate drunk driving case last fall.

MacKay, who resigned from Liberal caucus last weekend, is accused by a former member of his riding association's board of directors of driving drunk on Nov. 22, 2018, and weaving along the road in his vehicle before eventually crashing into a light pole. He then had to be pulled from his car and taken somewhere to sleep.

The explosive allegations are contained in an email from last May that the unidentified person sent to the president of the Chester-St. Margaret's riding association as they offered their resignation from the board of directors.

In the email, which was also sent to caucus staff, it is alleged people decided not to call the police on MacKay in order to preserve his and other people's jobs.

On Tuesday, McNeil said he only learned of the new charges against MacKay and the allegations last week.

On Wednesday, after being grilled during question period for a second day about who knew what, McNeil confirmed to reporters that his chief of staff, Laurie Graham, was made aware of the allegations when they were first received in May.

"We were doing a trade mission in Europe when she would have received a call that said to her there was this allegation, that it had been investigated and there was no substance to it and that was the end of it."

MLA Hugh MacKay enters court in Halifax on Nov. 8, 2019, before being sentenced on a charge of failing a breathalyzer. (Jean Laroche/CBC)

During question period, McNeil said "The [riding association] president at that time has said that he investigated that, didn't find the issue to be credible, Mr. Speaker, and did not inform the premier."

A spokesperson for the premier later clarified via email that "there wasn't a formal 'investigation,' though the matter was looked into it was determined it had no credibility. The chief of staff then made a number of follow-up inquiries and also deemed the allegations not to be credible."

The premier's office has not yet said who contacted Graham to make her aware of the allegation, or who she followed up with. Graham was not available for an interview Wednesday.

Not all allegations need to reach the level of the premier, McNeil told reporters.

"All kinds of stuff arrives to my office. The job of the chief of staff is actually to determine [what] actually gets to me and [what] actually has substance, which are the ones I have to deal with."

The email includes the claim that the author has text messages and video evidence of what happened that night. The premier said he's not aware of what attempts were made by party officials to see that evidence, but he reiterated that anyone with such evidence should bring it to police.

He said there appeared to be no evidence contained in what people in the party received.

"It's no different than me making and putting in writing a bunch of allegations about you with no evidence to take it to somebody," he said. "There's no evidence to determine what's in that letter, whether it is true or not."

'A real sad situation'

Environment Minister Gordon Wilson, who was Liberal caucus chair from about October 2018 until he was named to cabinet last April, said at no time were any allegations about MacKay drinking and driving brought to his attention.

When a reporter asked if he'd bring such an allegation to the premier's attention if he received it, Wilson said, "obviously, yes."

Tory Leader Tim Houston called it "a real sad situation" and said the Liberals "chose to do nothing" when confronted with allegations that one of their members was struggling with a problem.

"The Liberal Party knew about this for a long time. They had an opportunity to step up, step in and help their member. They didn't have to wait," he told reporters.

Houston said he can't imagine an allegation so serious not being brought to the attention of a party leader.

"If the premier didn't know about this, it speaks to a very, very dangerous culture within his party," he said. "If somebody on my team got an email like this, I would absolutely expect that they would escalate that to their supervisor and that that person would escalate it to their supervisor, because actions should have been taken."

For the courts, says NDP

Houston said after MacKay pleaded guilty in the fall, the party should have revisited the earlier allegations against him.

NDP Leader Gary Burrill said issues of criminality ought to be addressed in the courts, not on the floor of the legislature.

"I don't think the legislature is, in fact, very well geared up for that purpose."

The premier said he's not talked with MacKay since the most recent allegations.

He said MacKay remains in treatment for an illness that "is crippling for many Nova Scotians."

"It is my hope that he will continue to get well and the courts will deal with whether these allegations have substance."

MORE TOP STORIES