The prime minister found himself offering up a defence Friday in the face of an onslaught of criticism from Mulroney over foreign affairs policy, Canada's relationship with the U.S. and Harper's public fight with the Supreme Court.
On the 30th anniversary of his historic majority election win this week, the 75-year-old Mulroney suggested the Tories weren't in step with Canadian traditions and history because of their strained relationship with the United Nations.
He pointed to Canada's last failed bid for a seat on the security council as evidence of a bigger problem.
The former prime minister said the government's foreign affairs policy "has to be enveloped in a broader and more generous sweep that takes in Canadian traditions and Canadian history in a much more viable way.
"We're in the big leagues ... so we have to conduct ourselves in that way. We can't be out-riders," he said in an interview with CTV's "Power Play."
He also suggested the government had no clout internationally because the current prime minister lacks close ties to U.S. President Barack Obama.
But in Wales for the NATO summit, Harper said that Canada's ability to "contribute concretely in international affairs" has never been higher, "whether it's on the hard-powered side like the military, or the things we've been doing on development, particularly our leadership on child and maternal health."
He added: "I think those are the facts and I think they're widely recognized in the world and by Canadians."
Harper severed ties with Mulroney back in 2007 over the former prime minister's business dealings with German lobbyist Karlheinz Schreiber.
It took the two men years to reconcile both in private and in public.
Two years ago, Harper took the unusual step of reaching out to Mulroney directly to get political advice on Quebec, and the two were together last fall at an event to promote the Canada-E.U. Free Trade Agreement.
They've jokingly bickered in public over the deal, in seeming good faith, with Harper saying it is a bigger win for Canada than the North American Free Trade Agreement that Mulroney secured in 1993.
The Conservative Party fundraising machine revved up its gears over the trade deals on Friday as well, using the anniversary of Mulroney's win to remind party faithful not just of NAFTA, but the fact that the current government has widened its portfolio of trade pacts far more than any government in history.
"We're better off with Prime Minister Stephen Harper — and we need to have his back," the letter said.
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