The source of friction is a front-page article in Thursday's Mirror which reported that Prince Harry had been injured playing rugby at Eton. The newspaper reproduced a letter from a St James' Palace aide refusing permission for the newspaper to report exactly what had happened. The Mirror reproduced the letter with the details of the injury blacked-out.
Prince Charles's office is angry at the report and complained to the PCC under clause 6 of the commission's code of conduct, which prohibits reporting of children without parental permission.
The complaint is the latest in a series of efforts by the palace to clamp down on the reporting of the two princes. The Mail on Sunday apologised after it ran a birthday supplement about Prince William that attributed thoughts and opinions to the prince. The palace was also upset by stories about Prince Harry getting a short haircut.
St James' Palace issued a statement yesterday: "The Prince of Wales is deeply disappointed by the reaction of the editor of the Daily Mirror to the simple and straightforward appeal for Prince Harry to be allowed privacy at school. This is not a matter of press freedom, but about the ability of the Princes to grow up without intrusion."
However, The Mirror was refusing to apologise, claiming that the palace was being inconsistent. "We are not going to back down," said Piers Morgan, the editor. "In the first place it is a legitimate story to report on the health of an heir to the throne.
"In fact, I was given the story about Harry's arm by a member of Charles's staff. If they keep going for us I shall have to start revealing where we get some of our stories that paint them in a favourable light.
"And they have complained about us, for not running the story and have done nothing about the Daily Star which ran the story in full. In fact, a St James' Palace official told me there would have been no complaint if we had run the story on an inside page ... It's a joke ... It is not the job of the palace or the PCC to determine how prominent stories should be."
Mr Morgan added: "They are trying to rein in the press because they have been extremely bruised over the last few weeks. After helping with Penny Junor's book [Charles: Victim or Villain?] and some of the documentaries, it's all gone wrong for them and they are trying to target us."