Among them was ex-social worker Liz Davies, a leading child protection expert.
Organisers insist it is not in conflict with the Government’s inquiry but will instead complement it.
However, its website suggests that there will be an element of competition. It says: ‘This tribunal is necessary because the Government initiative has serious shortcomings.’
Questions have also been raised about its funding. Organisers say they hope to raise money from the public, partly by selling wristbands carrying the slogan ‘sweep away the secrecy’.
The tribunal will hold public hearings across Britain at which abuse survivors will tell their stories, and will produce a report within a year that will be submitted to Theresa May’s inquiry as well as other institutions.
As it is entirely unofficial, it has no legal powers requiring witnesses to come forward.
Mrs May will face questions from MPs tomorrow on the lack of progress with the investigation and the struggle to find a suitable chairman.
At least 100 names have been put forward after Mrs Woolf had to step down, following The Mail on Sunday’s revelation that she has close links to former Home Secretary Leon Brittan.