Former prime minister Brian Mulroney has spoken out publicly for the first time about his rift with Prime Minister Stephen Harper.

In an interview with CBC News, Mulroney said he is not concerned about the loss of Harper's friendship.

"He severed relations with me, which, when you've been prime minister, doesn't really mean very much to you. There's nothing that I worry about [that] Mr. Harper can or cannot do," Mulroney said. "That's his decision."

Relations between Mulroney and Harper cooled after the latter called an inquiry in January 2008 into Mulroney's affairs with German-Canadian businessman Karlheinz Schreiber.

Harper also told Conservative caucus members to stay away from Mulroney until the inquiry was over.

In March 2009, senior Conservatives told reporters that the former PM had not renewed his party membership — a charge Mulroney denied by saying he will be a party member until he dies.

In his interview with CBC, Mulroney also spoke about how to elect a majority Conservative government — and the risk of being perceived by Canadians as leaning too far to the right.

"Because you can’t elect anybody based on that hard-core thing," Mulroney said. "Mr. Harper was smart enough to realize that and to figure out how you get elected in this country.

"I was conservative — right of centre — on some important issues, which he is, and slightly left of centre, or centrist, on some important social issues," Mulroney added.

CBC's full interview with Mulroney will air on The National on Sept. 4, which is the 25th anniversary of his first majority victory.

Laureen Harper, the prime minister's wife, is due to attend a party next month to mark the anniversary of Mulroney's election win. The prime minister will be in the United States at the time for meeting with President Barack Obama.

With files from The Canadian Press