But Harper stood accused Thursday of turning a deaf ear to the core message of the 77-year-old Aga Khan by choosing not to invite the NDP and Liberals to an event Friday in Toronto to mark the visit.
The snub had the two opposition parties in an uproar, coming as it did one day after they took Harper to task for refusing to include them among an official Canadian delegation to Ukraine this week.
"We've got to learn to work together," said NDP Leader Tom Mulcair, who along with his Liberal counterpart, Justin Trudeau, was allowed to meet the Aga Khan Thursday on Parliament Hill.
But no invitation was extended to the opposition parties for Friday afternoon's event at Toronto's Massey Hall. At least two Conservative cabinet ministers and one senator are on the guest list.
"The Aga Khan is a model for working together and reaching out to other people, so it's a shame that for that event tomorrow in Toronto no one else seems to have been invited," said Mulcair.
Added Liberal foreign affairs critic Marc Garneau: "This is a highly-partisan government that behaves that way."
Harper spokesman Jason MacDonald responded that both opposition leaders were invited to join the prime minister for a meeting with the Aga Khan before he addressed the Commons.
"The event in Toronto will be an opportunity for thousands of Ismailis and non-Ismailis to hear His Highness speak," MacDonald said in an email.
"Invitations were extended to thousands of people from the community, as well as senior executives from the Toronto Star, Globe and Mail, Quebecor Media, Postmedia, and other media organizations — to say nothing of CEOs and charitable sector leaders."
The political fracas followed a speech in which the Aga Khan called on Canadians to join him in making the world a more tolerant, peaceful place.
"Canada is a leader in the community of nations," he told MPs and senators in a joint session of Parliament.
"I happily recall the establishment of the delegation of the Ismaili Imamat here in 2008 and the prime minister's description that day of our collaborative efforts to make Canada 'the headquarters of the global effort to foster peace, prosperity and equality through pluralism.'"
He was welcomed with repeated standing ovations in the packed Commons. The audience in the galleries included many Ismaili Muslim representatives invited for the occasion.
The Harvard-educated religious leader spoke elegantly in both official languages, mixing humour and history as he offered a solemn plea for peace in a badly divided world.
He opened by paying tribute to Canada's recent gold-medal Olympic hockey victories and joked that, as an honorary Canadian citizen, he would have liked to have played for the team.
"The Dalai Lama and I would have been a formidable defence."
The Aga Khan, hereditary holder of his religious office, is a regular visitor to Canada, with his most recent trips coming in 2008 and 2010.
In 2006, the Aga Khan opened the Global Centre for Pluralism in Ottawa, which is housed on Sussex Drive, just down the road from the prime minister's official residence.
He was granted honorary Canadian citizenship during the 2010 visit.
He said his foundation would help Canada celebrate its 150th anniversary in 2017.
The Aga Khan made a plea for greater understanding of the world's Muslims, noting that how they are viewed in the world is shaped by "the lens of war."
He lamented the growing divisions among Shia and Sunni Muslims around the world, especially in war zones such as Iraq, saying those disputes are not based on profound differences in religious faith.
"It is becoming a disaster," he said.
The world needs to pay more attention to the role of civil society, he said, which represents "voices for change where change is overdue ... voices of hope for people living in fear."
Religious intolerance and hostility seem to be on the rise around the world and can be countered by vigorous civil society, he argued.
And he commended Harper for establishing an Office of Religious Freedom, saying it could be a model for other countries.
He closed by quoting a verse from the Qur'an that the human race was born from a "single soul" — inspiring another sustained standing ovation.
Harper introduced the Aga Khan as a tireless humanitarian, lauding him for development partnerships in Africa, Asia and Afghanistan. The prime minister also said Canada had signed a protocol with him to deepen co-operation.
"When you are in Canada, you are home," said Harper, adding that the Alga Khan's advocacy for tolerance and pluralism has gone "beyond words."
Harper also thanked the Aga Khan for supporting his child and maternal health initiative, launched in 2010.
"Canadians are strongest when we have the support of those who share our values," Harper said.
"Your highness, I value your counsel and your friendship."
The Aga Khan became the 49th Imam of the Shia Ismaili Muslims in 1957, and oversees a number of foundations which run development projects around the world.
There are about 100,000 Shia Ismaili Muslims in Canada.
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