Diana was a patron of homeless charities before her death in 1997

Prince William said in a recent interview that he believes his late mother Princess Diana would be “disappointed” by the lack of progress on homelessness since she championed the issue in her lifetime.

“I think she would be disappointed that we are still no further on, in terms of tackling homelessness and preventing it, than when she was interested and involved in it,” the Prince of Wales said in a video that will air on BBC One in the U.K. on Friday.

The 40-year-old royal spoke to two people who have experienced homelessness during the video for homeless charity Groundswell ahead of Comic Relief’s Red Nose Day, an annual fundraising campaign.

“My mother introduced me to the cause of homelessness from quite a young age, and I’m really glad she did,” William told two people who had experienced homeless, adding that he wanted to speak to them to “learn” from their “lived experiences.”

Prince William, right, said Princess Diana introduced him to the homeless issue from a young age. (Getty)

“Homelessness is about not having a safe space – it’s a very isolating life,” a man named Miles told William during the podcast, according to the BBC. “You exist, you don’t live.”

A woman named Nawshin told him, “I didn’t have a choice but to leave home – I had a lot of childhood trauma and circumstances happened around me that were out of my control.” She had also experienced homelessness and said she had been in and out of mental health centers for a period of time.

Prince William is a patron of two homeless charities, Centrepoint and The Passage.

Last month, William helped The Passage open two buildings that can house more than 200 people each year.

Princess Diana became a patron of the Centrepoint homeless charity in 1992. (Tim Graham Picture Library/Getty Images)

“The work that I have seen first-hand over many years is the reason I know that ending homelessness must be thought of as more than simply a wishful aspiration,” he said at the event, according to the BBC. “Instead, it should be viewed as an achievable goal, one that working together we can and must accomplish.”

He added, “I am personally more determined than ever to play my part in working with others to do all we can to stop the human tragedy that is homelessness.”

Prince William slept on a London street in 2009 to raise awareness about the issue. (Anwar Hussein/WireImage)

Diana became a patron of Centrepoint in 1992 – 13 years before William did in 2005 – and she brought both William and Prince Harry there as children to help them understand the issue.

In 2009, William decided to sleep on a street in London to get a first-hand idea of how homeless people live.

Prince William, right, became a patron of Centrepoint 13 years after his mother did. (Anwar Hussein Collection/ROTA/WireImage)

“For me, it was a scary experience,” Centrepoint’s chief executive Seyi Obakin, who slept next to William that night, later wrote of the experience on the Centrepoint website, according to the Guardian. “Out of my comfortable bed. Out there in the elements. Out there on an extremely cold night, with temperatures down to minus 4. And it was the same for Prince William. But he was determined to do it as [Centrepoint] patron in order to raise awareness of the problem and to be able to understand a little better what rough sleepers go through night after night.”

He added they were “almost run over by a road sweeper which simply didn’t see our small group huddled together, which just goes to show how vulnerable rough sleepers are. I have never been happier to welcome the break of dawn.”