While a spokesperson confirmed that Harry will skip the service in Westminster Abbey on March 29, he is reportedly set to attend the Invictus Games starting in the Netherlands just two weeks later.
After days of front-page coverage about Russia's invasion of Ukraine, The Sun newspaper carried the headline: "Harry's Phil snub."
Royal biographer Angela Levin accused the California-based Harry of "blackmail" regarding the service for his grandfather Prince Philip, after the U.K. government withdrew his royal protection detail.
The second son to heir-to-the-throne Prince Charles "has snubbed the Duke of Edinburgh (Philip) but really he is snubbing the queen", Levin told U.K. media.
Prince Philip, who was married to the queen for 73 years, died last April just weeks short of his 100th birthday.
His funeral was held under strict coronavirus restrictions, with just 30 mourners including Harry. The queen sat alone, respecting the government guidelines.
Given the restricted nature of the funeral, this month's memorial service is meant to offer an opportunity for a national celebration of the Duke of Edinburgh's long life and service.
Harry's spokesperson Friday did not give a reason why he will miss it, but said he hopes to visit his grandmother "soon".
The funeral was one of only two occasions that Harry has returned to the U.K. since he and wife Meghan quit royal life and moved to North America two years ago.
As a result of their decision, the U.K. government withdrew his taxpayer-funded protection on visits back to Britain, a decision that Harry is challenging in the courts.
Commentators queried why Harry would feel unsafe visiting Britain but not the Netherlands for the Invictus Games, a sporting event he founded for disabled military veterans that starts in The Hague on April 16.
ITV News royal editor Chris Ship tweeted that Harry was pressing ahead with his attendance at the week-long event, but had "concluded he isn't safe in (the) U.K. without the access to intelligence he has asked for".
Harry is filming a behind-the-scenes documentary about the Invictus Games as part of a multi-million-dollar deal with Netflix.
Queen Elizabeth meanwhile has pulled out of attending another service in Westminster Abbey, for Commonwealth Day on Monday, after a period of fragile health including a mild bout of Covid.
