The head of the independent inquiry into historic child sex abuse is coming under growing pressure to stand down, as a lawyer representing victims said her social relationship with former home secretary Lord Brittan "puts her beyond the pale in terms of her credibility".
Fiona Woolf yesterday confirmed she had attended two dinner parties at Lord Brittan's house and hosted the Tory peer and his wife on three occasions, but insisted she did not have a "close association" with the former cabinet minister.
She told a parliamentary committee scrutinising her appointment that the former home secretary - who has denied failing to act on a dossier of abuse allegations in the 1980s - was "one of thousands" of people she knew in London.
But solicitor Alison Millar, who represents a number of abuse victims whose cases are likely to be raised in the inquiry, said the "general view" among her clients was that Mrs Woolf - the Lord Mayor of the City of London - "really does not have the necessary credibility to lead what is such an important inquiry for them".
Asked whether Mrs Woolf should step down, Ms Millar told BBC Radio 4's Today programme: " Yes. I think this evidence of dinner parties with Lord Brittan really puts her beyond the pale in terms of her credibility with my clients."
Mrs Woolf was appointed in September to chair the independent panel inquiry into UK institutions' handling of child sex abuse allegations, after the initial nominee Lady Butler-Sloss stepped down over suggestions that she might be called upon to investigate the role of her late brother, former attorney general Lord Havers.
Downing Street has said Prime Minister David Cameron is "confident that Fiona Woolf and the panel will carry out their duties to the high standards of integrity required".
Ms Millar told Today: "This is not about Fiona Woolf's ability or her integrity. This is about her independence and her ability to lead this inquiry in a way that is credible to the survivors of abuse whom I represent.
"S omebody who seems to be on dinner party terms with a senior political figure whose knowledge this inquiry will be scrutinising is somebody who from the perspective of my clients does not have the necessary independence.
"The people that I am in contact with because they are my clients, or I am in contact with otherwise, the general view among them is that Fiona Woolf really does not have the necessary credibility to lead what is such an important inquiry for them."
Corporate lawyer Mrs Woolf, who lives in the same street as Lord Brittan, yesterday released a letter detailing the extent of her social links with the former minister.
She told the House of Commons Home Affairs Committee that, as well as attending dinner parties with Lord Brittan, she had met his wife for coffee, sat on a prize-giving panel with her, and sponsored her £50 for a fun run.
But she described him as "essentially someone who is one of thousands of people who I know in the City", and insisted there was nothing in the encounters to stop her chairing the wide-ranging probe ordered by Home Secretary Theresa May.
Mrs Woolf appeared unwilling to say Lord and Lady Brittan were not friends, and could not remember whether they were on her 3,000-strong Christmas card list last year. But she said their numbers were not programmed into her mobile phone.
As a newly elected alderman of the City of London Corporation, she had hosted hundreds of dinner parties to "build my City network" at a time when Lord Brittan was a vice-chairman of UBS bank.
Mrs Woolf insisted she did not regard herself as "a member of the establishment".
"I can understand that there will be people who do not know what the Lord Mayor of London does," she said. "But as an ordinary solicitor in private practice I really do not think I count as a member of the establishment."
Mrs Woolf said she had no background in child protection or family law, indicating that she would take a managerial approach to the inquiry.
"I am determined that this inquiry is going to relentlessly uncover the truth for the victims," she told the MPs.
In a statement to the Commons earlier, Mrs May reiterated her backing for Mrs Woolf. She said she believed the inquiry panel - which will also include Rotherham sex abuse report author Professor Alexis Jay - would "carry out their duties to the highest standards".
But Labour MP Simon Danczuk, who led the campaign for an inquiry, said Mrs Woolf and Lord Brittan were "clearly good friends" and she should stand down as chairwoman.
Lord Brittan is likely to be called to give evidence to the inquiry over a dossier he received from MP Geoffrey Dickens in 1983, documenting the alleged involvement of VIP figures in a child sex ring.
Abuse survivor Phil Frampton, who supports other victims of abuse in care homes, told Today: "I am absolutely appalled at Fiona Woolf's appointment. It's like putting Wayne Rooney in charge of an investigation of the nuclear energy industry.
"What appals me is that this is about very, very serious crimes and horror for children, and adults who are living with it still.
"It's like putting a few puppets in place to deal with the seriousness of the situation."
Another victim of alleged abuse in local authority care, who could not be named for legal reasons, told the Today programme: "Everyone deserves a chance, but I thought she lacks a huge amount of credibility from a victim's perspective.
"She talks about 'victim communities'. There is no such thing as a victim community. All the victims have had to live their lives in mainstream society carrying some terrible, terrible scars and being ostracised by society by and large.
"And yet we have the lord mayor of London to represent victims. It's laughable."
But inquiry panel member Sharon Evans - chief executive of the Dot Com Children's Foundation and a sexual abuse survivor - told Today: "I am very confident that this inquiry can do its job.
"We have Graham Wilmer, who is another victim... We have representatives of HMIC (HM Inspectorate of Constabulary), we have a family law barrister who's been in care himself.
"I think there's been so much focus on Fiona Woolf, which I understand, but she is just the head of the panel. There are nine people in total, with an enormous background and expertise in this."
Ms Evans added: "The whole panel are aware that we've got off to a very difficult start, but what we discussed between us yesterday is that we are satisfied that Fiona Woolf has the skills of a solicitor ... We need balance and we need those skills that will give us that kind of balance.
"I would like people to be reassured that there are victims on this panel and we are determined to get to the bottom of this. One of the things that Graham and I hope is that the fact we are here and we are part of this will give people confidence. We do want to listen.
"I will give you my pledge that I will not let anybody get away with things that I think have been covered up. I know from talking to all the panel members, who have so much experience, that they are equally passionate about that."
Liberal Democrat MP John Hemming called on Mrs Woolf to stand down, describing her appointment as "a mistake".
Mr Hemming, who was one of the first MPs to call for an inquiry, told the BBC: "Appointing Fiona Woolf is ... a mistake. She's clearly a fully fledged member of the establishment.
"I think she should stand down because an independent observer would think there's a possibility of bias. It's not to say that she is inherently biased, it's just that her personal contacts would give no confidence to the victims that have been ignored for many years."
Mr Hemming also raised concerns over the inquiry's terms of reference excluding events in Jersey, pointing out that former DJ Jimmy Savile was pictured at a care home on the island where children are believed to have suffered abuse.
Deputy Prime Minister Nick Clegg said he had no evidence that Mrs Woolf had not been thoroughly vetted, but appeared to stop short of offering full support.
Answering questions after delivering a speech in south London, the Liberal Democrat leader said: "We all need to have confidence that the decisions taken by the Home Secretary ... were thorough.
"I have not heard anything that suggests to me the process by which Theresa May made the recommendation is anything other than thorough."
Liberal Democrat MP John Leech tabled a parliamentary motion calling for Mrs Woolf to be replaced by a chair "who has palpably demonstrated ... willingness to challenge all quarters of the establishment to ensure that (the inquiry) can achieve its aims of providing justice to the victims of historic child abuse".
The early-day motion also warned that the inquiry's terms of reference, announced yesterday by Mrs May, threaten to "severely compromise" its effectiveness, because they propose that the panel should not take evidence from individual victims but collate information from previous reviews.
It calls for the creation of a dedicated police team in the National Crime Agency to work alongside the inquiry to investigate and prosecute offenders.
Manchester Withington MP Mr Leech said: " I want an inquiry that the victims of historic sex abuse can have faith in, that allows the victims the chance to give evidence, that challenges the establishment and makes clear that those who have done wrong, or covered up abuse, are going to be brought to justice.
"I don't think that can happen with Fiona Woolf as the inquiry chair."
The motion is co-sponsored by three other MPs, including Mike Hancock from Portsmouth South, who gave an unreserved apology at London's High Court earlier this year over what he acknowledged was an ''inappropriate and unprofessional friendship'' with a female constituent suffering from mental health problems.
Early-day motions are not debated or voted on in the Commons, but provide an opportunity for MPs to voice their opinions on topical issues.
Asked whether Mr Cameron still has full confidence in Mrs Woolf, the Prime Minister's official spokesman said: "Yes, because if you look at her background - including as President of the Law Society - I think she brings experience to the role as head of the panel."
The spokesman added: "Of course I understand why there is significant interest in the work that the panel is going to be doing and it is important that we and others explain why we are confident that this panel she will oversee can get to the bottom of this.
"I would point both to her experience and also to the experience from the panel who will work with her. There are two members of the panel who have been victims of abuse and will bring the experience of the work they have been doing with victims of abuse to bear on the work that the panel is doing."
In response to Mr Leech's complaint that the terms of reference should allow the panel to take evidence directly from victims, Mr Cameron's spokesman said: "The Prime Minister believes that the terms of reference are the right ones.
"The central point here is that this independent panel inquiry will look across the board at the extent to which institutions have failed in their duty of care to protect children and, very importantly, draw on the work of other investigations and other inquiries."
Shadow energy secretary Caroline Flint, has told BBC2's Daily Politics it was "really difficult" for Mrs Woolf to remain as chair.
"I don't blame her," she said. "The Government ... had a second chance to do this properly and they've put this woman in a really difficult position now and they need to sort it out.
"I just don't think at this stage it's viable that she's the person that leads this and takes it forward."
Ms Johnson called on Mrs Woolf and the Home Secretary to meet abuse survivors.
"We have said right from the start that anyone chairing this inquiry should have the full support of the survivors of abuse - both Fiona Woolf and Theresa May should meet survivors groups immediately to address their concerns," she said.
" Theresa May must now move quickly to demonstrate that both the process behind the inquiry and the person appointed to lead it have support from the majority of survivors - otherwise the inquiry will fail before it even starts."