Two newspapers have been criticised by the Press Complaints Commission (PCC) over reports Euan Blair had applied for a place at Oxford.

Prime Minister Tony Blair and wife Cherie complained after Daily Telegraph and Daily Mail articles which they said invaded their son's privacy.

But the PCC has warned that it would become more difficult to protect Euan's privacy if he started making regular public appearances.

He was recently filmed attending the premiere of Iris with a female friend, who was the subject of press speculation.

'Unnecessary intrusion'

And he has been the victim of negative press coverage before after being found drunk and incapable in London's West End and, more recently, after reports civil servants helped with his homework.

The Blairs complained about the Daily Telegraph report headed "Quiet flows the don as Euan opts for Trinity" and a follow-up piece in the Daily Mail.

They said the articles broke the press Code of Practice section 6.1 on children, which says "young people should be free to complete their time at school without unnecessary intrusion".

Nothing should be written about them simply because of the position of their parents, the code insists.

The Daily Telegraph argued there was a legitimate public interest in reporting where prime ministers chose to educate their children.

Robust Blairs

But the PCC has ruled against it, with the text of a full adjudication expected later on Monday.

It is expect to say public interest would only apply if the choice of college had been at odds with government policy or a public statement by the Blairs.

The Blairs have robustly defended their privacy, attacking unjustified pressure from newspapers to reveal whether their son Leo was given the controversial MMR vaccine.

But in an apparent reference to the Iris film premiere, where Euan was photographed with Kate Winslet, the PCC will say it is more difficult to protect an individual where they began to acquire a public profile in their own right.

Complaint upheld

It will indicate privacy is best maintained when not compromised in any way.

A PCC spokesman said: "There has obviously been a complaint from the Blairs against the Telegraph and it has been upheld.

"We cannot give you the wording of the commission's adjudication because of a procedural point.

"Newspapers and the complainants are given an opportunity to see the wording prior to our publication.

"We have not been able to get in touch with the relevant people at the newspaper to confirm that there are no objections."

Public domain

The Daily Telegraph said it would make a statement later on Monday.

The Mail argued the information was already in the public domain when it followed up the story.

While "suggesting" to the Mail it should resolve the matter with the Blairs, the PPC is not expected to make a formal adjudication.

Robin Esser, executive managing editor at the Daily Mail, said the newspaper had no comment to make but was considering the PCC ruling "very seriously".