This is something the Department of Foreign Affairs is working on. Private think tanks have postulated there could be as many as four million or five million Canadians who have dual citizenship. Some of them would be overseas, some would be in Canada. But the nature of dual citizenship makes it impossible to know if someone leaves the country and accepts citizenship in another country. We don't necessarily know that. It's a difficult number to obtain, but the Department of Foreign Affairs is working on it.
On November 7th, 2006. See this statement in context.