Pratt waded into the national media last Sunday with revelations that several Downing Street staff had phoned her charity's helpline.
She spoke out after Lord Mandelson dismissed claims in a new book that Prime Minister Gordon Brown had bullied staff.
But Pratt has been condemned by PROs and the media for breaching the confidentiality of her helpline’s users.
In an email to PRWeek, Pratt wrote: ‘I write this in tears as I no longer know what to do or say for the best. Whatever I do, someone will be hurt. I did not set up a helpline with any intention of causing distress to others.'
She added: ‘I am unable to talk to you at this time. I am sorry.’
PRWeek broke the story on Tuesday that Pratt had turned to Max Clifford for help with the media onslaught.
Meanwhile theCharity Commission has just launched a formal inquiry into the helpline after receiving over 160 complaints about its behaviour this week.
As a temporary and protective measure, it has ordered the charity to prevent the transmission or disclosure of information, including about the nature and source of the confidential calls it has received, without the permission of the Commission.
The Commission has a statutory responsibility to promote public trust and confidence in charities. The body said it is aware of the potential impact of this issue on other charities that run confidential helplines.