The announcement — which the government refused to acknowledge Friday — comes 22 months after the Tories first promised to create a modest, religious freedom branch within the Foreign Affairs Department.
The pledge was unveiled in the Conservative campaign platform during the last federal election, but Foreign Affairs has been unable to find a commissioner to take the job.
Human rights groups and opposition critics have said the office is a misguided attempt to inject religion into foreign policy.
They also question what exactly the new office can accomplish with a modest $5-million budget.
However, a spokesman for a major Jewish organization invited to Tuesday's event said the fact the Harper government is holding it at a mosque shows its commitment to persecuted religious minorities the world over.
The Ahmadiyya Muslim community centre and mosque, a complex in Vaughan, Ont., has been selected as the venue.
Len Rudner, spokesman for the Centre for Israel and Jewish Affairs, said the location makes an elegant statement about the Conservatives' commitment to shining a light on religious persecution through its new office.
"The Ahmadiyya Muslim community is a very important community, and frankly it is a community that has known its fair share of persecution as well," said Rudner, who has received an invitation to Tuesday's event.
"It's very commendable that the government looks for opportunities, not only in terms of the words that it speaks, but also the place where it plants its feet to show it is serious about religious freedom for all faiths and all communities."
Rudner said he's excited about hearing more details about the new office.
He called it a worthy initiative that will help expose abuse suffered by religious minorities in all corners of the globe.
"There is a real need for people in the world to speak out in support of religious freedom and speak out in support of those who are denied that freedom in countries around the world," said Rudner.
"It's good for the Jewish community worldwide, but I think it's good for all religions."
Foreign Affairs Minister John Baird won't be on hand for the announcement because he'll be in the middle of a six-country Latin American trip.
But his cabinet counterpart, International Co-operation Minister Julian Fantino, is expected to attend because the mosque is in his riding.
Baird has been involved in many high-level meetings with religious figures over the last 18 months.
His consultations have taken him to the Holy See in Rome, the Aga Khan, head of the Greek Orthodox Church in Turkey and the U.S. ambassador at large for international religious freedom.
The Tories have pointed to the fact that the U.S. State Department's religious freedom office was created in the late 1990s under the Democratic administration of Bill Clinton.
In an interview with The Canadian Press last year, Baird cited persecution of Baha'i practitioners in Iran, Coptic Christians killed in Egypt and Roman Catholic priests who have been forced underground in China.
A 2011 briefing note to Baird, obtained by The Canadian Press under Access to Information, laid out three priority areas for the new office: protecting, and advocating on behalf of, religious minorities under threat; opposing religious hatred and intolerance; promoting the Canadian values of pluralism and tolerance abroad.
Government sources said the Conservatives had a hard time finding someone to lead the office. Its modest $5-million price tag includes $500,000 for operations.
NDP foreign affairs critic Paul Dewar said Friday he's curious to see who runs the office, and what their religion is.
"If you appoint someone from any particular faith by design, it's going to be a bit of a controversy, because you know, why not another religion? ... We warned them about this," Dewar said.
"We said there's nothing wrong with the promotion of religious freedom, but it should be done in the context of human rights in general."
Tuesday's announcement comes after many fits and starts that saw government officials touting the imminent creation of the office over the course of the last year.
But the plans for the announcement were well under way with invitations sent out to a select group of people.
Toronto Liberal MP Jim Karygiannis wasn't on the invite list, but he told The Canadian Press that senior officials of the Ahmadiyya Muslim community centre told him they were ready to host the event.
"The Conservatives probably wanted to have a tight ship," Karygiannis said Friday.
Karygiannis said the Conservatives took too long to set up the office. He said the government's main motivation in setting it up was to win votes in key Toronto-area ridings during the last federal election.
The Conservatives have maintained that the seed of the idea came after Prime Minister Stephen Harper met with Pakistan's minister for minorities, Shabhaz Bhatti, shortly before he was shot to death by extremists in Islamabad in 2011. The extremists accused Bhatti, a Christian, of violating Pakistan's controversial blasphemy law.
Bhatti's brother, Peter, has been invited to Tuesday's event, according to a report in the weekly publication, Embassy.
"I am very excited," Bhatti said in the report. "His sacrifice in not going to be in vain."
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