Image copyright Paul Chiasson

Prince William and the Duchess of Cambridge's visit to a Canadian charity that supports pregnant women struggling with addiction will be a "wonderful closing of the loop" of the work Princess Diana did in that same realm some 25 years ago, says the organisation's manager.

On Sunday, the royal couple will visit Sheway, which has helped vulnerable mothers since 1993 in Vancouver's Downtown Eastside, an area of the city that has become synonymous with urban poverty and substance abuse.

The visit is part of the upcoming Canadian tour by Will and Kate, and one of their first engagements over the week-long visit.

Manager Patti Zettel, who described the duke and duchess's planned visit as "mind-blowing," noted Sheway was modelled on a facility in Glasgow, Scotland, that had received Princess Diana's support.

"It shows a commitment to a particular group of marginalised individuals - women and addiction - for a quarter of a century now by the royal family," she said.

Image copyright Courtesy of Dr Mary Hepburn Image caption Princess Diana at the official opening of the Glasgow Women's Reproductive Health Service Unit in 1990

Princess Diana, Prince William's mother, embraced a wide range of humanitarian causes before her death in 1997. She advocated for the homeless and vulnerable youth, and took a personal interest in some unpopular causes of the time, including people with HIV/Aids.

The Sheway stop itself is brief - it's expected to last about an hour - but is important to the programme's clients.

"It's a validation that their lives and their experiences have meaning and that their stories deserve to be told," Zettel said.

Besides the visit to Sheway, over the course of some 30 separate engagements the duke and duchess will pay tribute to veterans of the Afghanistan conflict, will visit staff and volunteers who helped support Syrian refugees recently welcomed to Canada, will meet first responders, will travel to the Great Bear Rainforest - the world's largest temperate rainforest - and will meet a number of First Nations communities.

While the tour itinerary nods to Princess Diana's legacy and doesn't shy away from social issues, it also offers many opportunities to showcase the breathtaking natural beauty of British Columbia - Canada's western-most province - and the Yukon, a territory in the country's north.

Nathan Tidridge, who has written extensively on the monarchy, said Canadians rarely spend time thinking about the royal family despite the fact that Queen Elizabeth is the Canadian monarch.

Image copyright Reuters Image caption Prince William and the Duchess of Cambridge are honorary members of the Canadian Rangers

Still, Tidridge said Canadians will tune in due to the "glossy magazine" aspect of the youthful royal family. By highlighting efforts towards reconciliation with Canada's First Nations, conservation and charity work, these tours help "tell our national story".

"Any moments that gather us together as a community are really, really, important. It's those intangible moments that royal tours really offer us," he said.

This is Will and Kate's second visit to Canada as a couple. They were previously in Canada in 2011, shortly after their wedding.

The Duke and Duchess will travel with their two young children, Prince George and Princess Charlotte.

As during the 2011 visit, the family is expected to be a popular draw.

Shachi Kurl, executive director of the polling group Angus Reid Institute, said coverage of royal tours in Canada tends to be positive, and Canadian opinion on the royal family tends to be personality driven - many like and respect the Queen and her grandson Prince William, though have lukewarm feelings towards the Prince of Wales.

But they are divided over the role of the monarchy in this country.

"When you remove the personalities from the equation and ask the bigger question about who should be our head of state, should we continue as the monarchy, or is that an outdated notion - there you do see some pretty big division in this country," she said.

Carolyn Harris, an historian and author, said that Will and Kate, as young, modern and relatable royals, have sparked a renewed interest in the royal family among Canadians.

"There is a sense now of there being a very clear future for the royal family [in Canada]."

Image copyright Press Association Archive Image caption Prince William and Kate at the the Calgary Stampede in Calgary, Alberta

ITINERARY

24 Sept Victoria, British Columbia: Their Royal Highnesses, accompanied by their children Prince George and Princess Charlotte, arrive in Victoria, the capital of British Columbia.

25 Sept Vancouver, British Columbia: The Duke and Duchess will visit Sheway, the Immigration Services Society of British Columbia, an event celebrating young leaders in Canadian arts, music, sport, charity, business, and film, and finally the visit the Kitsilano Coastguard Station.

26 Sept Bella Bella and the Great Bear Rainforest, British Columbia: The Duke and Duchess will travel to the Great Bear Rainforest, visit with the Heiltsuk First Nations community and attend a reception hosted by the province of British Columbia at Government House.

27 Sept Kelowna, British Columbia and Whitehorse, Yukon: They will tour the Okanagan campus of the University of British Columbia and take part in the BC Government's "Taste of British Columbia" festival at Mission Hill Winery before flying to Whitehorse, where they will be greeted by members of the Canadian Rangers.

28 Sept Whitehorse and Carcross, Yukon: Will and Kate will visit the MacBride Museum and meet members of Whitehorse's cultural community before travelling to Carcross, where they will be welcomed by the Carcross/Tagish First Nation.

29 Sept Victoria, British Columbia: The royal couple and their children attend children's party in the grounds of Government House, which will be attended by military families.

30 Sept Haida Gwaii, British Columbia: The Duke and Duchess visit Haida Gwaii, the archipelago on the northern coast of British Columbia and is home to the Haida Nation. They will attend the opening of the new Haida Gwaii Hospital and Care Centre. They will join local youth for a fishing expedition on the waters of Hecate Strait.

30 Sept Victoria, British Columbia: The royal couple will visit the Cridge Centre for the Family, which provides services and support for women who have experienced domestic violence. They will then meet families who have received support from the Kelty Mental Health Resource Centre and later youth working with the Sail and Life Training Society. They end their tour with a public official departure ceremony at Victoria Harbour Airport.