Mr Green said that many of the stories involved information already in the public domain, some that was put out by the Royal household, some by the Duke himself and some obtained from confidential sources.

He said it was “quite extraordinary” that the judge had been asked to infer the stories had been obtained unlawfully.

He highlighted one article that had been broken by the News of the World.

The story, published in January 2002, alleged that Harry had been taking drugs. The only new information the Mirror had added was that the young Prince had not been back to the pub in question, Mr Green told the judge.

“Mr Sherborne said that you could infer that that additional information was obtained by UIG (unlawful information gathering),” he said.

“There was plainly no voice interception. There is no payment record so why should there be any inference of UIG. What UIG? By who?”

He said the additional information was almost certainly obtained by journalists.

“It is exactly the sort of information that journalists get hold of,” he said.

“You are invited to infer that it’s UIG. That absolutely doesn’t work.

“It’s become rather fantastical.”