New regulations on harassment and privacy will be announced today by Lord Wakeham, chairman of the Press Complaints Commission.
They are expected to include a formal definition of harassment that will allow the PCC to clamp down on publications whose staff take part in "collective harassment which is not justified by the nature of the event".
The stricter harassment definition is designed to prevent the kind of paparazzi tactics that played a part in the death of the princess.
It is understood that some editors have told Lord Wakeham that they were concerned that the new rules should not allow MPs to escape the attentions of investigative journalists by crying "harassment" if they have something in their personal or financial affairs to hide.
Also to be included is an extension of the restriction which bars photography of individuals in private places to areas such as churches and restaurants "where individuals might reasonably expect a degree of privacy".
These exclusions are designed to tighten the current rules about reporters and photographers intruding on people during times of "shock and grief", particularly funerals.
The new regulations for the public are on top of agreements reached by newspaper editors not to intrude on the lives of Princes William and Harry up to and past their 16th birthdays.
The changes to the code of conduct, which have been described as the most extensive in the history of the PCC, were agreed at a full meeting of the commission in London yesterday.
Sir David English, editor-in-chief of the Daily Mail, said: "We have to review everything in the light of what's happened in the last month.
"I think the media does respond to public opinion because the media is commercial and to a large extent the public have the power to make the media do what they want."
The Broadcasting Standards Commission has called on broadcasters and politicians to rethink the balance between freedom of speech and public offence after a British National Party election broadcast brought complaints from 76 viewers.Reuse content