Men and women who say they were sexually abused by Catholic priests as children have begun a conference in London, ahead of the Pope's visit to Scotland and England.
They plan to offer messages to the Pope and compile them in a book for him.
Pope Benedict XVI is due to arrive on 16 September for a four-day visit.
Meanwhile, in a BBC poll of 500 Catholics, 52% said the scale of abuse, and the way it was handled, had "shaken their faith" in the Church leadership.
The poll conducted by ComRes - a member of the British Polling Council - surveyed the random sample of Roman Catholics across the UK between 6 and 9 September 2010.
On this first visit by a pope to the UK since John Paul II in 1982, the pontiff will go to Edinburgh, Glasgow, London and Birmingham.
Saturday's London conference is being hosted by support group Minister and Clergy Sexual Abuse Survivors (MACSAS).
The group was set up to support survivors of sexual abuse by clergy from all Christian denominations, whether abused as children or as adults.
This year's conference - called We Speak, You Listen - will focus on Catholic survivors, offering the chance for them to relay messages about their "stories, hopes and dreams" to Pope Benedict.
Their testimonies will be compiled into a book, with the title 'The testament we give you, hear us', which they hope to present to him.
Catholic survivors of clergy abuse who could not attend were asked to send their stories and comments ahead of the conference.
Celibacy 'safe haven'
Peter Saunders was abused by two priests when he was a child and now runs a charity for child abuse survivors, the National Association for People Abused in Childhood.
He told the BBC's Allan Little: "Because abusers pass some of the responsibility to their victims, you're left thinking, 'I can't really say anything because maybe I did something, maybe in some way it was my fault, I deserved it'.
He added that the Catholic Church seemed to have done "a phenomenal job of covering up, moving on abusing priests and denigrating their victims".
The Church has said child abuse is no more prevalent among its clergy than in society in general, but some argue that the celibacy required of the priesthood has played a role.
Psychologist and Jesuit priest Brendan Callaghan told the BBC the commitment to celibacy appeared to "offer a safe haven for people".
But he added: "Eventually those currents in a person's personality are going to surface. And when they do emerge, it's problematic."
A series of sex abuse scandals have rocked the Catholic Church around the world in recent years, with the Church further accused of maintaining a culture of secrecy.
Pope Benedict's supporters say he has been the most proactive pope yet in confronting abuse.
Earlier this year he apologised to victims of child sex abuse by Catholic priests in Ireland, and later went on to promise "action" over child abuse by priests.
Many campaigners accept that the Catholic Church in England and Wales and in Scotland has done much to acknowledge the problem and to try to eradicate it, said our correspondent.
But some survivors say they still carry the psychological scars and that the Church should do more to fulfil their duty to them.
MACSAS campaigner, Dr Margaret Kennedy, said: "They have abandoned the victims. They talk about this historical abuse quite extensively. Well it's not historic to the victims. It's now."
