A defamation lawsuit against Premier John Horgan is expanding, and while the government doesn't seem to want to admit it, it could end up costing taxpayers.

Former BC Liberal leader Gordon Wilson is doubling down on a $5 million lawsuit against Horgan and the province's jobs minister, now looking to include the media.

Wilson led the party from 1987 to 1993, and served as MLA for Powell River-Sunshine Coast from 1991 to 2001.

But most recently, Wilson was an LNG advisor under the Christy Clark Government. He took home $150,000 a year until he was fired by the new NDP regime.

Wilson says his reputation was damaged by an allegation that he "did little more than file an expense account" during his time in the LNG role. Contrary to the suggestion, Wilson produced many documents during his time as an advisor.

"It's highly defamatory… It's been devastating," he told CTV News Tuesday.

The premier apologized for the allegation, and added he hoped everyone would move on. The apology didn't fly with Wilson, so he sued the premier and others for defamation.

The defendants want the case thrown out, saying they spoke based on the information they had at the time.

Horgan brushed off questions about whether taxpayers would foot the bill for his legal costs.

"I'm not sure I can confirm that. Certainly there was a request for an indemnity," he said.

Talks to settle the case out of court broke down, Wilson said. He added that if the case goes to trial, things could get costly.

"I don't know how we can predict that. We haven't really begun any court proceedings that I'm aware of, so I don't know if the costs are significant or not," Horgan said.

With a report from CTV Vancouver's Bhinder Sajan