The plaintiffs, who include John’s husband, David Furnish, and actors Elizabeth Hurley and Sadie Frost, accuse the publisher of the Daily Mail of paying private investigators to illegally bug homes and cars and to record phone conversations.

Harry said the publisher targeted him and the people closest to him by unlawfully hacking voicemails, tapping landlines and obtaining itemized phone bills and the flight information of his then-girlfriend, Chelsy Davy.

The publisher, Associated Newspapers, asked the judge to throw out the case. At hearings in March, the company’s lawyers argued that the claims — which date as far back as 1993 — were brought too late and that the plaintiffs were relying on confidential evidence the papers turned over to a 2012 public inquiry into tabloid wrongdoing.

Judge Matthew Nicklin ruled that the plaintiffs cannot rely on the documents handed over to the 2012 Leveson inquiry. But he said the case can go ahead because the claims “have a real prospect of succeeding.”

“Associated has not been able to deliver a ‘knockout blow’ to the claims of any of these claimants,” the judge said in a written ruling.

The other plaintiffs are anti-racism campaigner Doreen Lawrence and former politician Simon Hughes.

The case is one of several lawsuits brought in Britain by Harry, who has made it a personal mission to tame Britain’s tabloid press.

In June, he became the first senior member of the royal family to testify in court in more than a century when he testified in a separate phone-hacking lawsuit against the publishers of the Daily Mirror.

Harry is also suing the publisher of the Sun tabloid alongside actor Hugh Grant. That case is scheduled to go to trial early next year.