Prince Harry risks 'lobbing a grenade' at Prince William as chance to heal yearslong feud emerges: expert

Prince Harry’s return to the U.K. could offer him his best chance yet to reconcile with his estranged brother, Prince William, but royal experts say a major obstacle remains in his way.

A source told People magazine that Harry's return to Britain presents the "best opportunity" to repair his fractured relationship with Prince William.

"It would never happen with him in America," the insider said.

"This gives them [an] opportunity to try and mend that bridge." PRINCE WILLIAM ‘INCANDESCENT WITH ANGER’ AT PRINCE HARRY AS DIANA ANNIVERSARY DEEPENS ROYAL RIFT: PIERS MORGAN But royal experts told Fox News Digital that Harry's reported plans to consider making a documentary about Princess Diana could threaten that opening, giving the Prince of Wales another reason to remain wary of his younger brother.

"I don't buy this," royal broadcaster Helena Chard told Fox News Digital.

"Harry says [he and his family] relocated for so many different reasons, but the main reason is clear: it's the reported planning of the Diana documentary for the 30th anniversary." "This isn't bridge building," she said.

"This is lobbing a grenade at Prince William's feet.

Prince William has said no to every Diana documentary offer.

He doesn't want to speak so openly about Diana.

And also, doing this would just drain him if he was going to do it as a working royal.

He doesn't want to create publicity for Prince Harry's documentary, and he also doesn't want him and Harry pitted against each other as brothers." WATCH: PRINCE HARRY'S POSSIBLE DIANA FILM IS ‘GRENADE’ AT PRINCE WILLIAM'S FEET: EXPERT "Friends also say that next year is going to be tough enough," Chard continued.

"Prince William just wants to let his mother rest in peace.

So, he’s likely going to want to do something privately.

Enough is enough, he thinks." Fox News Digital reached out to Archewell and Kensington Palace for comment.