William says Diana would be disappointed at level of homelessness
Prince William says his mother, Princess Diana, would have been disappointed at the lack of progress in preventing homelessness.
He shared his thoughts during a video recorded for this year's Red Nose Day charity appeal.
Making the video, the Prince of Wales spent time with people who had been helped by a homelessness charity.
His comments will be shown on BBC One on Friday as part of the annual appeal to raise funds for Comic Relief.
As a child, Prince William was brought by his mother on visits to charities working with homeless people, such as the Passage in central London.
"My mother introduced me to the cause of homelessness from quite a young age, and I'm really glad she did," said the prince, in the video to be shown during the Red Nose Day appeal.
"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."
Comic Relief quotes official government figures which reveal that rough sleeping in England has risen by 26% in a year, which it linked to a "spiralling cost-of-living crisis".
It also warned that the numbers of those sleeping on the street remained the "tip of the iceberg" in terms of the wider problem of homelessness.
Prince William spoke to people who had been supported by the Groundswell charity, funded by Comic Relief.
This included Miles, who told the prince: "Homelessness is about not having a safe space - it's a very isolating life. You exist, you don't live."
Another person in the video, 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."
Prince William is patron of the Passage homelessness charity. Last month he opened two residential buildings which will support 225 people per year.
At the opening ceremony in London, in February, he rejected the idea that homelessness was "inevitable", saying "ending homelessness must be thought of as more than simply a wishful aspiration. Instead, it should be viewed as an achievable goal".
"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," said the prince.