Immigrants to Canada will have to keep taking an oath to the Queen Elizabeth II after the Supreme Court of Canada refused Thursday to hear a challenge to the citizenship requirement.

The decision by the top court leaves intact an Ontario Court of Appeal ruling.

At issue is a provision in Canada's Citizenship Act that requires would-be citizens to swear to be "faithful and bear true allegiance to Queen Elizabeth the Second, Queen of Canada, her heirs and successors."

Queen Elizabeth II is Canada's titular head of state. Canada is a member of the British Commonwealth of former colonies.

Longtime permanent residents Michael McAteer, Simone Topey and Dror Bar-Natan challenged the law because they do not want to pledge allegiance to the monarchy.

Informed of the Supreme Court decision that ends the battle, McAteer, 81, of Toronto, said he was disappointed but not surprised.

"It's been a long haul," said McAteer, a staunch republican who came to Canada from Ireland 51 years ago. "(But) I feel the same: If the oath stands, then I won't take Canadian citizenship."

Topey, a Jamaican Rastafarian, said her religion forbids taking an oath to the Queen. Bar-Natan, an Israeli, argued that the oath represents entrenched privilege he opposes.

The federal government maintained that taking the oath has been around since Confederation.

In its ruling, the Ontario Court of Appeal noted the Queen remains Canada's head of state, calling the oath a "symbolic commitment to be governed as a democratic constitutional monarchy unless and until democratically changed."

Lawyer Peter Rosenthal said the high court refusal to hear the case doesn't necessarily indicate an endorsement of the oath — but simply means the justices didn't feel the case was worthy of their attention.