Press Complaints Commission head Baroness Buscombe is to step down in the wake of the News of the World phone hacking scandal.
In a statement released on Friday she said she was "proud" of her work at the PCC and wished to contribute to the Leveson inquiry.
She called for tougher powers to police press misconduct and defended her organisation, saying it needed increased powers but should not be shut down.
"First, the public rightly demands stronger powers for dealing with the misconduct of the press. They must get them.
"Second, the public needs the existing work of the PCC to continue and be built upon. I have worked as Chairman to ensure that we give real help (both before and after publication) to members of the public, who otherwise would have no-one to turn to. The staff of the PCC are unsurpassed in terms of the effort and intelligence they bring to their work.
"And third, the importance of a free press has never been greater. It was thanks to investigative journalism that the phone hacking scandal was brought to public attention. Newspapers and magazines must have the proper freedom to represent their readers' interests, and also to expose wrongdoing wherever it may be found.
"In this world of shifting media provision, I am convinced the answer to ethical concerns about the press is not statutory intervention. What is needed is a greater sense of accountability among editors and proprietors. A PCC with increased powers and reach remains the best way of achieving that."
The chair of the press watchdog had been criticised for the PCC's response to the scandal. She previously said News International had lied to her.
"Yes, I am the regulator, but there's only so much we can do when people are lying to us. Now we know. We didn't have the evidence then. We know now that I was not being given the truth by the News of the World.
"Who knows whether there are other papers who have lied," she told the BBC on July 5.
Buscombe and the PCC have been criticised by politicians, with Ed Miliband and Nick Clegg calling the organisation "toothless". David Cameron said the PCC was unfit for purpose.