The fifth-in-line to the throne is due to give evidence at London's High Court as part of his legal action against the publisher of the Daily Mirror over phone-hacking allegations - one of four cases he is pursuing against British tabloids.

Since he and his American wife Meghan stepped down from royal duties in 2020 and moved to California, he has made it his mission to rid of those he accuses of being "criminals masquerading as journalists" from running the newspapers.

"They have lied under oath, perjured themselves in the process and have proven they're above the law. Everyone seems to be scared of them, especially politicians," he said in a witness statement released as part of his phone-hacking case against Rupert Murdoch's News Group Newspapers.

He said he felt incredibly strongly about the issue, "not just in a personal capacity but as part of the role I have always taken on, in terms of my duty to stand against things which are unjust and which people without the same resources, or the wider public, should not have to accept or undergo".

Harry's dislike of the press goes back decades, to the death of his mother Diana in a Paris car crash as her limousine sped away from chasing photographers, an incident he said could have been avoided if she had not dispensed with police protection, fearful they were leaking stories to the media.

In the last few months, he and Meghan have detailed at length their treatment from tabloids in a Netflix documentary, TV interviews and his memoir "Spare".

Their accusations that the royal family, including those working for his brother Prince William and his stepmother Camilla, now the queen consort, colluded in media "lies" have cast a shadow over his father's first few months on the throne.

Newspapers reject his allegations of unlawful behaviour while his detractors, of whom there are unsurprisingly many in the media, say his court battles might take the gloss off the king's grand crowning.

'HYPOCRITE'

"As Prince Harry predictably does his best to wreck his father's coronation with yet more privacy lawsuits & rants about the privacy-invading media, a reminder that the biggest, most ruthless invader of privacy in royal history - for gazillions of $$$$ - is... Hypocrite Harry," journalist and broadcaster Piers Morgan said on Twitter.

But those who say wealthy publishers have not been brought to account for wrongdoing and unethical behaviour, praise Harry for embarking on what he said his father had described as "probably a suicide mission" when others, including his own relatives, are too fearful.

"I think he's incredibly courageous to do what he's doing because we know historically how powerful the press in the UK is as an institution," Steve Barnett, professor of communications at Westminster University, told Reuters.

"I don't think he's got that much to lose, given the vilification that he has suffered from the British press over the last 15 years."

Whether his actions change anything in the long-term is to be seen, while Les Hinton, a former long-time lieutenant of media mogul Murdoch, described the relationship between media and monarchy as a vital alliance.

"You'll never hear any public acknowledgement from the royal family of this mutual dependency, but it's a fact," Hinton wrote in the Times, one of Murdoch's British papers.

"Nevertheless, the dynamic duo of monarchy and media — although neither talk of their intertwined dependence — are hard at work to ensure the coronation is smash-hit entertainment. There is profit for them both in doing so."

For Harry himself, who saw military service twice in Afghanistan, his written statements to court have made it clear he is not going to give up his cause without a fight.

"It is clear to me that the tabloid press are the mothership of online trolling," he wrote.

"People die as a result of trolling, and people will continue to take their own lives when they can't see any other way out. How much more blood will stain their typing fingers before someone can put a stop to this madness?"