A child sex abuse inquiry's fourth chairwoman has said some forces want to stop a light being shone on "dark institutional failings" after a victims' group quit the probe, branding it an "unpalatable circus".
Professor Alexis Jay vowed to push on with the Independent Inquiry into Child Sexual Abuse (IICSA) after the Shirley Oaks Survivors Association (Sosa) and Labour MP Chuka Umunna called for her replacement.
Sosa delivered a blistering critique of IICSA - calling it a "stage-managed event" which has "lurched from crisis to crisis".
But Prof Jay, writing in The Times, said: "I have fought for this inquiry - for its independence, its reputation and its vital capacity to right a terrible wrong - since it opened, and I don't intend to stop fighting for it now.
"There are some people who would like to see us fail because it suits their agenda to not want dark institutional failings brought into the light.
"But shine that light we will, because there are many, many people in this country who spend every waking minute of every day living with the damage and the pain caused by child sexual abuse."
Sosa, which represents victims affected by abuse at children's homes run by Lambeth Council in south London, said it feared Prof Jay is "an uninspiring leader" who is not the right person to uncover the truth.
Downing Street and Home Secretary Amber Rudd have voiced their support and panel member Drusilla Sharpling said Prof Jay's work exposing prolonged abuse in Rotherham meant she had the expertise needed.
Sosa chairman Raymond Stevenson said members voted on Saturday that they no longer wanted to be part of the inquiry.
"The inquiry needs to sort itself out. They need to get rid of Alexis Jay, who's been parachuted in by the Home Office. She's not the right person," he told the BBC Radio 4 Today programme.
Labour MP Chuka Umunna said he did not have confidence in Prof Jay as chair of the inquiry and wanted a judge of High Court level or above to replace her.
An inquiry spokesman said: "Our investigation will continue and will examine the scale and nature of the abuse that may have taken place under the care of Lambeth Council with pace, confidence and clarity."
The inquiry, first established by then home secretary Theresa May in 2014, has been fraught with problems and controversy.
Described as the most ambitious public inquiry ever launched in England and Wales, it is running several investigative strands spanning decades.
Following her resignation earlier this year, former chairwoman Dame Lowell Goddard said there was an "inherent problem" in the inquiry's "sheer scale and size".