Heather Mills McCartney is to sue two newspapers over "false, damaging and immensely upsetting" statements surrounding her divorce from Sir Paul, her lawyers said today.
Solicitors Mishcon de Reya named the the Daily Mail and the Evening Standard as the subject of legal proceedings. Legal action will also be taken against The Sun.
In a statement, Heather's legal representatives said she had been vilified in the media and was now being stalked by photographers.
They said the 38-year-old could not afford to sue all the newspapers she wanted to.
"Her time and resources are not infinite. She cannot sue – for now, at least – every single newspaper that has published false, damaging, and immensely upsetting statements about her.
"She should not thereby be taken to have accepted that these statements are true."
The storm over the McCartneys' increasingly bitter divorce began last Tuesday when legal papers were leaked to the press.
The document, apparently prepared by Mishcon de Reya in answer to Sir Paul's divorce petition, contained allegations that he mistreated his wife during the couple's four-year marriage.
The ex-Beatle, through his lawyers, insisted he would "vigorously" defend himself against the claims.
Since then, the couple have rarely been out of the headlines.
Mishcon de Reya said: "It would appear that the media has concluded that there are no limits to what may be said about, or done to, our client."
The lawyers said it was "entirely false" that Heather had been offered a £30 million divorce settlement from Sir Paul.
"The truth is that no settlement offer, in any amount, has been made. She is pursued everywhere she goes.
"She is stalked by press photographers, who congregate outside her home and chase after her in cars – regardless of her safety or the safety of her daughter."
Mishcon de Reya issued a copy of a letter, apparently from The Mail on Sunday's investigations editor Dennis Rice, offering Heather's sister Fiona a "substantial sum" for information about the divorce.
It said the letter was hand-delivered and promised anonymity.
"It requires no imagination to conclude what kind of information was being sought from our client's closest confidante, nor why the assurance of confidentiality was believed to be necessary."
The statement finished: "We ask on behalf of our client for the media, as a matter of common decency, please now to show some restraint."