Montreal - As foreign dignitaries and Canadian politicians gather to commemorate the 400th anniversary of Quebec City, there will be one conspicuous absence on the guest list.

Prime Minister Stephen Harper will lead an international delegation of politicians at a ceremony Thursday morning in the shadow of the castle-like Chateau Frontenac Hotel to salute the arrival of French explorer Samuel de Champlain on July 3, 1608.

France will be represented by Prime Minister Francois Fillon. British High Commissioner Anthony Joyce Cary will represent Britain, which conquered Quebec City following the battle on the Plains of Abraham in 1759.

Fearing a nationalist backlash in the mainly French-speaking province, the governing Conservatives avoided inviting British Queen Elizabeth II, Canada's head of state, to participate in the year-long celebrations to mark the founding of North America's oldest continuously inhabited European settlement.

To not invite the queen to an event like this is an insult to the queen," Robert Finch, head of the Monarchist League of Canada, told CTV News.

The office of the Canadian Heritage Minister Josee Verner, which is coordinating the organization of festivities on the federal level, did not respond to repeated interview requests by Deutsche Presse- Agentur dpa.

Even opposition leader Stephane Dion, who hopes to unseat the governing Tories, declined to comment.

Elizabeth's invitation is a touchy issue for the minority Conservatives. Prime Minister Harper has been courting soft nationalists in Quebec, hoping their votes would propel the Conservatives into a parliamentary majority.

Quebec has a strong separatist movement that almost won a 1995 referendum to secede from Canada.

The federalist provincial government of Premier Jean Charest, too, has to walk a tight rope.

The British monarchy has never been particularly popular in Quebec, where the memory of France's humiliating defeat to Britain in the Seven Years' War (1756-63) still lives on and even provincial car license plates declare, "Je me souviens (I remember)."

In 1964, during the queen's royal visit to Quebec City, baton- wielding police had to disperse a noisy demonstration of Quebec separatists chanting, Elizabeth stay at home."

Her opening of the 1976 Montreal Olympics did not go over well with Quebec nationalists, either. The federalist provincial government that had invited Elizabeth to the Summer Games was soundly defeated by the separatist Parti Quebecois that same year.