A Toronto man publicly recanted "the royalty part" of the mandatory Oath of Allegiance to the Queen moments after becoming a Canadian citizen on Monday, choosing to pledge his "true" loyalty only to Canada and its people.

Dror Bar-Natan, a math professor from Israel, says the monarchy is a symbol of inequality and calls the portion of the oath dealing with it "repulsive." But he believes strongly in the rest of the pledge that deals with citizens' responsibilities.

"I'm definitely proud to be a Canadian," the 49-year-old said after the ceremony. "It's a wonderful country, a truly wonderful country, with one small iota that I disagree with."

Bar-Natan was one of three longtime permanent residents who challenged the constitutionality of making citizenship conditional on the pledge to the Queen, her heirs and successors.

In upholding the requirement, Ontario's top court said the Queen remains Canada's head of state and the oath was a "symbolic commitment to be governed as a democratic constitutional monarchy unless and until democratically changed."

The court also found, however, that all citizens have the right to espouse anti-monarchist views and new Canadians could publicly disavow what they consider to be the message conveyed by the oath.

Bar-Natan explained that his actions on Monday were fully in line with the court's findings.

"For a long time I was held back from taking citizenship because of the allegiance to the Queen and her heirs and successors part of the oath. I never felt comfortable with that," he said. "I hope this paves the way for others."

At a citizenship ceremony in east Toronto, Bar-Natan first swore the oath along with some 80 others and then, while being handed his citizenship certificate, informed the citizenship judge of his intent to disavow the portion of the oath pledging allegiance to the Queen.

He formally recanted that part of the oath following the ceremony and handed the judge a letter explaining his decision.

Bar-Natan pledges 'true allegiance to Canada'

"I wish to affirm my allegiance, my true allegiance to Canada and the people of Canada, but also to disavow the royalty part and only the royalty part of the citizenship oath," Bar-Natan told the judge as others looked on.

"I hear you sir. And I thank you for your honesty," said citizenship judge Albert Wong, who shook Bar-Natan's hand. "I welcome you to Canada and I look forward to the contributions you will make."

Bar-Natan later said he had felt "somewhat humiliated" at having to say the oath at all, despite being able to disavow the part of it he disagreed with later.

"I do feel that it is comparable to hazing, the fact that you are required to stand up and express views that are opposite to yours," he said. "I don't think it is a part of Canada to impose political speech on others. To impose opinions on others."

Bar-Natan added that a website he has set up — disavowal.ca — will allow other Canadians to publicly disavow their pledge to the Queen, regardless of when they took their oath.

Bar-Natan's controversial decision sparked some strong reactions on social media.

"Strip him of citizenship the moment he disavows the oath. If he doesn't want to keep the oath, he shouldn't be made a Canadian," tweeted one person.

"Why do people come here if they have no intention of following the basic requirements," said another.

Bar-Natan's lawyer said he hoped his client's actions would draw the new Liberal government's attention to re-evaluating the wording of the citizenship oath that deals with the monarchy.

"He underlined how silly it is to require somebody to say it," said Peter Rosenthal. "I hope that will contribute to the public debate about this and the present Liberal government will do what the Chretien government almost did in 1994."

In the 1990s, former Liberal prime minister Jean Chretien was set to scrap the oath to the Queen but got cold feet at the last minute, then-citizenship minister Sergio Marchi has told The Canadian Press.