An animal advocacy group is urging Prince William and Kate to cancel their planned visit to the Calgary Stampede during their Canadian tour.

The People for the Ethical Treatment of Animals has been a long-standing critic of the Stampede's rodeo events, stating that animals are injured and killed for the sake of entertainment.

The Duke and Duchess of Cambridge are expected to attend some of the Stampede events and preside over the kickoff of the annual parade next Friday.

PETA's president Ingrid E. Newkirk warned William and Kate in an open letter to the royal couple that they are walking into a "hotbed of controversy" if they attend the event.

Virginia Fort, a senior campaigner at PETA, said that PETA hopes the royals will show mercy to the animals by not attending.

"The royal couple has a choice, they can simply not go and not endorse the Stampede," she told CTV.ca. "The animals don't have that choice."

Calgary is the last stop for the newlyweds, who just arrived in Canada on Thursday afternoon, before heading to the U.S.

Fort said that the Stampede uses devices that are illegal in Britain, like electrical shock prods, certain types of spurs and bucking straps – all designed to increase the spectacle.

"The electrical hot shots and bucking straps make the animal more riled up, they rise in pain," she said.

"The audience just sees it as entertainment."

Last year, six horses died during the rodeo events at the 10-day event.

With files from The Canadian Press