Prince Harry was treated unfairly when he was stripped of his British security detail, his lawyer told appeal court judges in London on Tuesday.

Harry, who made a rare appearance in court for the hearing, lost his government-funded protection in February 2020 after he stepped down from his role as a working member of the Royal Family and moved to the U.S.

A High Court judge ruled last year that a government panel's decision to provide "bespoke" security for Harry — custom-designed on an as-needed basis for his visits to the U.K. — was not unlawful, irrational or unjustified.

But lawyer Shaheed Fatima argued that a group that evaluated the Duke of Sussex's security needs failed to follow its own process and perform a risk management assessment.

"The appellant does not accept that bespoke means better," Fatima said. "In fact, in his submission, it means that he has been singled out for different, unjustified and inferior treatment."

Harry, whose titles include the Duke of Sussex, was wearing a navy blue suit and light blue tie as he sat behind his lawyer. His surprise appearance was an indication of the case's importance to him.

Harry, 40, the younger son of King Charles, has bucked Royal Family convention by taking the government and tabloid press to court, where he has a mixed record.

But Harry rarely shows up to court, making only a few appearances in the past two years. That included the trial of one of his phone hacking cases against the British tabloids when he was the first senior member of the royal family to enter the witness box in more than a century.

Claims that Harry and family are endangered

Harry had claimed he and his family are endangered when visiting his homeland because of hostility aimed at him and his wife Meghan, Duchess of Sussex, on social media and through relentless hounding by news media.

He lost a related court case in which he sought permission to privately pay for a police detail when in the U.K., but a judge denied that offer after a government lawyer argued officers shouldn't be used as "private bodyguards for the wealthy."

He also dropped a libel case against the publisher of the Daily Mail for an article that said he had tried to hide his efforts to continue receiving government-funded security.

But he won a significant victory at trial in 2023 against the publisher of the Daily Mirror when a judge found that phone hacking at the tabloid was "widespread and habitual."

WATCH | Harry wins case against Daily Mirror owner (2023): 

Prince Harry wins phone-hacking lawsuit against Mirror tabloid chain

Prince Harry is declaring victory after a London judge says he was a victim of phone hacking by the British publisher Mirror Group Newspapers.

He claimed a "monumental" victory in January when Rupert Murdoch's U.K. tabloids made an unprecedented apology for intruding in his life for years and agreed to pay substantial damages to settle his privacy-invasion lawsuit.

He has a similar case pending against the publisher of the Daily Mail.