Baroness Buscombe will quit after completing three years as head of the PCC
The head of the Press Complaints Commission (PCC) has announced she will step down after criticism of its handling of the phone-hacking scandal.
Baroness Peta Buscombe has chaired the watchdog since April 2009 but has faced a backlash over the saga, which led to the closure of the News of the World.
Baroness Buscombe said she would not continue in the role when her three-year term in office ends next year.
She will aid the Leveson phone-hacking inquiry as a media regulation expert.
Baroness Buscombe said in a statement: "I am pleased that the commission want me to continue in post until my successor has been appointed.
"Thereafter, I will be able to be a campaigner for change from outside the organisation.
"I wish to contribute to the Leveson inquiry and participate fully in the overall debate regarding reform, unfettered by my role as chairman of the PCC."
Code of practice Baroness Buscombe, 57, is a former lawyer and chief executive of the Advertising Association.
She was elevated to the House of Lords in 1998 and has been a Tory frontbench spokeswoman on several subjects.
In November 2009, she withstood calls to resign after she questioned lawyer Mark Lewis's evidence to MPs over phone-hacking allegations at the News of the World (NoW).
Mr Lewis brought a libel action against the PCC and Baroness Buscombe over the comments.
She also came under fire the same month for a report in which the PCC appeared to clear the NoW of phone hacking after after the paper's former royal editor Clive Goodman and investigator Glenn Mulcaire were jailed in 2007.
The PCC was established in 1991 to enforce a code of practice for UK newspaper and magazine publishers and editors.
Earlier this month, Prime Minister David Cameron accused the PCC of being "ineffective and lacking in rigour" and cited the need for a "new system entirely". Labour leader Ed Miliband said the self-regulatory body was a "toothless poodle".
The Metropolitan Police's Operation Weeting is investigating claims of phone hacking at the News of the World, which was closed after it emerged that the phone of murder victim Milly Dowler had been hacked.
In other developments:
- The Culture, Media and Sport Committee has voted not to recall Labour MP Tom Watson is asking the Culture, Media and Sport committee to recall News International chairman James Murdoch to give more evidence on phone hacking
- Allegations have emerged that News of the World illegally accessed the phone belonging to the mother of murder victim Sarah Payne
- BSkyB's board has unanimously agreed to keep James Murdoch as its chairman
- A man has admitted throwing a shaving foam pie at Rupert Murdoch
The culture committee has voted against recalling News International chairman James Murdoch to give more evidence on phone hacking.
Appearing before the committee earlier this month, Mr Murdoch said he had not been "aware" of an email suggesting hacking went wider than a "rogue" NoW reporter.
This was later disputed by ex-News of the World editor Colin Myler and the paper's ex-legal manager Tom Crone.
Labour MP Tom Watson had wanted the three men to be called to give evidence on the email but the committee instead decided to write to the men for more details.
Committee chairman John Whittingdale said it would also write to law firm Harbottle and Lewis, who investigated the phone hacking claims on behalf of News International.
Mr Whittingdale said the committee would meet again next month after it had received replies to its letters and "chances are" the MPs would then wish to take oral evidence.
Sarah's Law The latest development comes after the mother of murder victim Sarah Payne learned she may have been a phone-hacking victim.
Police told Sara Payne her details were in notes compiled by Mulcaire, who was used by the NoW, which championed her Sarah's Law child protection campaign.
According to a report in the Guardian, the evidence uncovered by police in Mulcaire's notes is believed to relate to a phone given to Ms Payne by the NoW's then-editor Rebekah Brooks "as a gift to help her stay in touch with her supporters".
The BBC has not been able to confirm whether the evidence relates to this particular mobile.
But Mrs Brooks, who left her role as NI chief executive because of the hacking scandal but denies having had any knowledge of the practice while at the paper, says the phone "was not a personal gift".
She said the allegations were "abhorrent and particularly upsetting as Sara Payne is a dear friend".
On Friday it was announced that James Murdoch had received the backing of the BSkyB board to remain as the company's chairman. The decision was confirmed in BSkyB's annual results statement.
BSkyB chief executive Jeremy Darroch told the Today programme the decision to keep Mr Murdoch in the position had been unanimous.
"I think James has got strong support in the shareholder base, he's got strong support in the management base and unanimous support in the board."
Mr Darroch said the board would keep a watching brief on external events but when asked what it would take to get Mr Murdoch to step down, refused to speculate.
Meanwhile, a man has admitted throwing a shaving foam pie at Rupert Murdoch as he gave evidence to a committee of MPs.
The News Corporation chairman was targeted as he answered questions about the phone-hacking scandal last week.
Jonathan May-Bowles, 26, of Windsor, Berkshire, admitted assault and causing harassment, alarm or distress when he appeared before City of Westminster Magistrates' Court.