This is the picture which last night intensified pressure on the head of the Government’s child abuse inquiry to resign.

It shows Fiona Woolf with Lady Brittan, the wife of former Home Secretary Lord Brittan, at an awards ceremony in October 2013. This is despite Mrs Woolf telling MPs that she had had no social contact with the Brittans since April 2013.

Victims of sexual abuse, their lawyers and MPs last night called for Mrs Woolf to resign over her dinner-party links to Lord Brittan, who is likely to be called to give evidence to the inquiry about allegations – which he denies – that he was at the centre of an Establishment cover-up of sex abuse claims.

Fiona Woolf (left) was with Lady Brittan (right) at the 2013 Dragon Awards at Mansion House in October last year - alongside journalist Martyn Lewis (centre) - but did not mention this meeting to MPs

There are calls for Fiona Woolf to quit after she admitted she entertained former Home Secretary Leon Brittan and his wife three times at dinner parties at her house, and twice went to his central London home for dinner

Corporate lawyer Mrs Woolf, who lives in the same Central London street as the Brittans, wrote a letter to Home Secretary Theresa May, in which she claimed her last social contact with Lady Brittan had been in April 2013.

Mrs Woolf, the Lord Mayor of London,boasted of having ‘carefully checked through my records’ to ensure she had not missed anything when she wrote to Mrs May. And she told MPs this week she had ‘gone the extra distance’ to produce an exhaustive list of contacts.

Last night a Home Office source insisted it was a ‘minor omission’, but Labour and Liberal Democrat MPs queued up to demand her resignation.

Critics said that, even if the mistake was an oversight, it did not bode well for the chairman of a sensitive inquiry to have such a flimsy grasp of the facts. As Downing Street and the Home Office desperately tried to prop up their candidate:

A group of victims launched a legal challenge to Mrs Woolf’s appointment on the grounds her friendship with the Brittans undermined her impartiality;

A senior Tory minister admitted Mrs Woolf would have to show she had the confidence of victims and ‘time would tell’ if she had that;

An abuse victim on the inquiry panel admitted it had got off to a ‘very difficult start’;

Labour said her position was ‘not viable’.

But the emergence of the picture was the most damaging revelation. It shows Mrs Woolf QC and Lady Brittan talking to former BBC newsreader Martyn Lewis at the Dragon Awards in October 2013. All three were judges of the awards, which recognise City firms’ contribution to the community.

In her letter to Mrs May, Mrs Woolf said: ‘I have had no further social contact with Lord and Lady Brittan since April 23, 2013, and have not spoken to either of them in person or by telephone since, other than disclosed in this letter.’

She told the Home Secretary that she and Lady Brittan were ‘both judges for the Dragon Awards in 2014’, adding the extra detail that Lady Brittan did not attend the 2014 awards ceremony.

But she makes absolutely no mention in her letter of the 2013 awards. Then on Tuesday this week, she offered additional reassurance to the Home Affairs Select Committee, telling its members: ‘I have gone the extra distance to make sure I have dug out any possible connection.’ Her assertion unravelled within 24 hours as the new photo emerged.

Home Secretary Theresa May has insisted the inquiry can go ahead, despite the chairman's links to Leon Brittan (right, with his wife)

On Tuesday, she offered additional reassurance to the home affairs select committee, saying: ‘I have gone the extra distance to make sure I have dug out any possible connection.’ Her assertion unravelled within 24 hours as the new photo emerged.

Last night committee chairman Keith Vaz said he was ‘surprised’ by the new information. He added: ‘It is important to give her the opportunity, as I will do when I write to her, to ask her why this particular piece of information was missing.’

THE SIX QUESTIONS FOR BRITTAN Lord Brittan is accused of burying a dossier given to him by MP Geoffrey Dickens in 1983. It documented the alleged involvement of VIP figures in a child sex ring. He has denied the claims. These are the unanswered questions: Why was the Dickens dossier either 'not retained' or destroyed by the Home Office?

Which officials had sight of the document?

Is there any record of the dossier with prosecutors or the police?

Dickens handed over another dossier in January 1984, apparently containing allegations of abuse in children's homes. What action was taken over this file?

The Home Office says it retains a file containing a letter Brittan sent to Dickens. Does it identify any individuals named by the MP?

Given his key role at the time, why was Brittan not contacted by the Home Office during its review into the handling of organised child sex abuse allegations – including the Dickens dossier? Advertisement

In her letter to Mrs May, Mrs Woolf made the damning admission that she had entertained the former Home Secretary and his wife three times at dinner parties at her house, and twice went to their home for dinner. But despite their social and professional contacts, she insisted she did not have a ‘close association’ with the peer.

Lord Brittan is accused of ignoring, or burying, a dossier given to him by MP Geoffrey Dickens in 1983, allegedly documenting the involvement of VIP figures in a child sex ring. He denies the claims.

Mrs Woolf made no further comment yesterday. A Home Office spokesman said: ‘Fiona Woolf has written to the Home Secretary setting out any issues, including her involvement in the Dragon Awards, which might be seen to cast doubt on her impartiality.

‘The Home Secretary is confident that this panel, under the chairmanship of Fiona Woolf CBE, will carry out a robust and thorough inquiry, and will challenge institutions without fear or favour, in order to get to the bottom of this issue and stop it from happening again.’

But Labour MP Caroline Flint said: ‘I just don’t think at this stage it’s viable that she’s the person that leads this.’ Asked if Mrs Woolf had the confidence of people involved in the inquiry, Cabinet Office minister Francis Maude told the BBC: ‘I think she will need to show that and time will tell.’

A lawyer representing victims said her social relationship with Lord Brittan put her ‘beyond the pale in terms of her credibility’. Alison Millar said ‘evidence of dinner parties with Lord Brittan really puts her beyond the pale in terms of her credibility with my clients’.

Lib Dem MP John Hemming called on Mrs Woolf to stand down, calling her appointment a mistake. One of the two victims of abuse sitting on the panel, Sharon Evans, said the inquiry had got off to a ‘very difficult start’.

The Home Secretary's first choice to lead the inquiry into historic child abuse was Baroness Butler-Sloss (left), but she was forced to step down because her brother was the Government's attorney general. Labour MP Simon Danczuk called for her to stand down

Has she misled Parliament?

If MPs conclude Mrs Woolf deliberately misled Parliament – of which there is no evidence – she could be hauled back before them to correct what she said.

Under an antiquated procedure last used decades ago, she could theoretically be forced to come to the House of Commons to be admonished publicly by the Speaker.

It is known as being ‘called to the bar of the House of Commons’. The last time a non-MP was summoned to the bar was on 24 January 1957.