The Duke of Sussex, 41, and six other claimants including singer Elton John are suing the Mail's publisher Associated Newspapers for violations of their privacy from the early 1990s until the 2010s.
Associated, which also publishes the Mail on Sunday, has called the allegations "preposterous smears", saying their journalists had legitimate sources for information, including from the celebrities' friends and acquaintances.
Having become in 2023 the first royal in 130 years to give evidence in court during another of his lawsuits against the press, the younger son of King Charles gave a combative response to questions from Associated's lawyer Antony White, but became emotional when he was asked about the case' impact.
"I think it is fundamentally wrong to have to put all of us through this again when all we were asking for is an apology and some accountability," he said.
"It is a horrible experience and the worst of it is that by sitting up here and taking a stand against them ..., they continue to come after me."
Choking up, Harry added: "They have made my wife's life an absolute misery."
Earlier he repeatedly rejected claims from White that its papers' journalists were close to his "leaky" social circle.
"For the avoidance of doubt, I am not friends with any of these journalists and I never have been," Harry said in often tetchy exchanges with White.
He added: "My social circles were not leaky. I want to make that absolutely clear."
The prince's case centres on 14 articles his legal team says were the product of unlawful information gathering, including by hacking voicemail messages, bugging landlines and obtaining private information by deception, known as "blagging".
Associated's lawyer White said the information in the articles was legitimately obtained, putting it to Harry that a former royal editor of the Mail on Sunday, Katie Nicholl, was part of his social group.
Harry replied: "If the sources were so good and she was hanging out with all my friends, then why was she using private investigators who have been connected to all the unlawful information gathering?"
He said he spoke to reporters and tried to be civil, but felt he had little choice despite feeling they had "commercialised my private life".
"These are people we were forced to work with, you had to have some kind of relationship with them ..., knowing who they are, knowing full well the kind of stories they have written about me," Harry said.
