Fiona Woolf confirmed that she lives on the same street as the former home secretary – who has flatly denied failing to act on a dossier of abuse allegations in the 1980s.
In a letter to Mrs May, the lawyer said she invited Lord and Lady Brittan to dinner parties on three occasions since 2008, and dined at their house twice. She also met the peer’s wife for coffee, sat on a prize-giving panel with her, and sponsored her £50 for a fun-run.
But the Lord Mayor of London – who is due to give evidence to the Home Affairs Select Committee later – insisted there was nothing in the encounters to stop her chairing the wide-ranging probe.
“Over the last few weeks, I have carefully checked through my records to ensure that there is nothing which should prevent me fulfilling that role,” she wrote.
“I have specifically focused, in the light of recent media reporting, on my contacts with Lord and Lady Brittan, but have not restricted my checks to those contacts.
“Having done so I am confident that I can continue to act.”
In a statement to MPs, Mrs May reiterated her backing for Mrs Woolf – only named as chair last month after original choice Lady Butler-Sloss stepped down because her brother was attorney general at the time some of the alleged abuse occurred.
Mrs May said she believed the inquiry panel – which will also include Rotheram sex abuse report author Professor Alexis Jay – would “carry out their duties to the highest standards”.
“Fiona Woolf has a long and distinguished career throughout which she has demonstrated the highest standards of integrity,” the Home Secretary said. “I am confident that she will lead the work of the panel with authority, and that under her leadership the panel will get to the truth of these issues.”
But Labour MP Simon Danczuk, who has led the campaign for an inquiry, said Mrs Woolf and Lord Brittan were “clearly good friends” and she should stand down as chair.
“I have serious concerns about the relationship between Fiona Woolf and Leon Brittan,” he said.
“I don’t buy into this idea that the Home Office could not find someone who was not connected to Leon Brittan.
“He is surely somebody who has to be investigated as part of the inquiry – not least because of his role as home secretary at the time.
“One mistake is forgivable, but to make the same mistake twice looks like they are trying to protect Leon Brittan.
“Survivors of abuse will undoubtedly be very concerned about the impression that there is something untoward.
“I think it is a total error of judgment by the Home Office.”
Mr Danczuk added: “I don’t move in Pimlico dinner circles, but the vast majority of people I know, if you have somebody round for dinner in your home, you would consider them a good friend.”
The Labour MP said a “cursory Google search” showed a connection between Mrs Woolf and Lord Brittan.
“It is impossible that the Home Office will not have known,” he added. “She should not be doing this job.”
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.
Mrs May set out terms of reference for the panel, which is due to produce an update to Parliament by May next year.
The Home Secretary said the terms of reference had been “drafted to ensure that this strong and balanced panel of independent experts can have full access to all the material it seeks, unless there is a statutory impediment to it doing so”.
The panel has been asked to consider whether public bodies – and other, non-state, institutions – have taken seriously their duty of care to protect children from sexual abuse and will consider matters from 1970 to the present, said Mrs May.
It will decide for itself how and where to focus its efforts, in order to complete its work and make recommendations within a reasonable timeframe.
A 10 Downing Street spokeswoman told a regular Westminster media briefing: “We are absolutely clear that Fiona Woolf and her team, with the terms of reference that have been set out today, will leave no stone unturned in getting to the truth of what happened in the past.
“The Home Secretary has this morning, in setting out these details, made clear she is confident they will carry out their duties to the highest standards of impartiality and integrity.”