Professor Alexis Jay has been appointed to head up the troubled inquiry into child sex abuse, it was announced today.

Home Secretary Amber Rudd said Ms Jay, who wrote a key report into abuse in Rotherham in 2014, would be promoted from the inquiry's advisory panel to take over from New Zealand judge Dame Lowell Goddard.

The move is intended to ensure some sort of continuity in the massive £100 million Independent Inquiry into Child Sexual Abuse (IICSA), after Dame Lowell dramatically resigned as chairwoman last week with no warning.

Ms Jay becomes the fourth woman to take the helm at the beleaguered probe which has been running in various guises for two years but has so far heard almost no evidence despite racking up huge bills.

Home Affairs Committee chairman Keith Vaz today warned it must be 'fourth time lucky' for the vast inquiry, which has already cost taxpayers £18million and is due to draw together a staggering 13 different probes.

The task was branded 'unmanageable' by former DPP Lord Macdonald last week.

Professor Alexis Jay wrote a key report into child sex abuse in Rotherham in 2014

The life-long social worker is expected to be paid less than Dame Lowell, who was handed a package worth £500,000 including relocation from New Zealand and a £360,000 annual salary, when the terms of her appointment are finalised.

Sources claimed Dame Lowell, appointed by then-Home Secretary Theresa May just over a year ago, had lost the confidence of senior staff and members of the inquiry panel.

Her resignation letter was immediately accepted by Mrs Rudd, who succeeded Mrs May in the Home Office last month.

Baroness Butler-Sloss and Dame Fiona Woolf both stepped down from the role last year after concerns about their links to the establishment.

Ms Jay's 2014 inquiry revealed that at least 1,400 children had been subjected to sexual exploitation in Rotherham.

HUGE TASK FOR AUTHOR OF THE ROTHERHAM REPORT Professor Alexis Jay has spent decades in social work. She became Chief Social Work Adviser to the Scottish Government in April 2011. But Ms Jay came to wider attention in 2014 when she penned a shocking report into child exploitation in Rotherham. It found 1,400 children were subjected to appalling sexual abuse in the area between 1997 and 2013. Girls as young as 11 were raped, abducted, beaten and intimidated - predominantly by men of Pakistani heritage. Mr Jay slammed 'blatant' collective failures by the local council, and heavily criticised South Yorkshire Police for not prioritising the issue. The report prompted a raft of resignations and further inquiries. She is visiting professor at Strathclyde University, where she chairs the Centre for Excellence for Looked After Children in Scotland. Prof Jay worked for more than 30 years in local government, most recently as a director of social services. Advertisement

Ms Rudd said: 'The Independent Inquiry has a vital role to play in exposing the failure of public bodies and other major organisations to prevent systematic child sexual abuse.

'I'm delighted Professor Alexis Jay has agreed to chair the Inquiry. She has a strong track record in uncovering the truth and I have no doubt she will run this independent Inquiry with vigour, compassion and courage.

'Let there be no doubt; our commitment to this Inquiry is undiminished.

'We owe it to victims and survivors to confront the appalling reality of how children were let down by the very people who were charged to protect them and to learn from the mistakes of the past.'

Prof Jay said: 'I am committed to ensuring this Inquiry does everything it has set out to do and does so with pace, with confidence and with clarity.

'Be in no doubt - the Inquiry is open for business and people are busier than ever working hard to increase momentum.

'The panel and I are determined to make progress on all parts of the Inquiry's work, including speaking to victims and survivors.

'I am determined to overcome the challenges along the way.

'I will lead the largest public inquiry of its kind and together with my fellow panel members we will fearlessly examine institutional failures, past and present and make recommendations so that the children of England and Wales are better protected now and in the future.'

New Zealand judge Lowell Goddard dramatically resigned as chair of the troubled inquiry into child sex abuse last week

Shadow minister for preventing abuse Sarah Champion said: ' We now need to see results from the inquiry.

'Survivors have had the courage to come forwards and share their stories, often for the first time, these now need to be acted on.

TIMELINE: HOW THE TROUBLED INQUIRY INTO CHILD ABUSE HAPPENED July 7, 2014 - Theresa May, then home secretary, announces a public inquiry with the remit of investigating whether 'state and non-state institutions' have taken seriously their duty of care to protect children from sexual abuse within England and Wales. Its chairwoman will be Baroness Butler-Sloss, a retired High Court judge. July 9 - Baroness Butler-Sloss faces calls to quit due to a potential conflict of interest over a family connection. Her late brother, Sir Michael Havers, was attorney general in the 1980s. Then prime minister David Cameron stands by the appointment. July 14 - Baroness Butler-Sloss steps down. September 5 - Dame Fiona Woolf, a leading tax lawyer and then Lord Mayor of the City of London, is appointed as the new chairwoman of the inquiry. October 22 - Child sex abuse victim launches a legal challenge against Dame Fiona's appointment over her suitability for the role. She is accused of having 'close association' with Lord Leon Brittan, the late Labour peer against whom allegations of sex abuse were later dropped. October 31 - Dame Fiona quits as chairwoman. February 4, 2015 - Mrs May tells the House of Commons she is disbanding the former inquiry into child sex abuse and setting up a new statutory inquiry. Dame Lowell Goddard - described as 'one of the most respected and experienced judges in the Commonwealth' - is announced as its chairwoman. March 12 - New inquiry is set up with same remit as first. April 29 - Dame Lowell announces the inquiry will conduct a full investigation into the issues surrounding the allegations of sexual abuse against Lord Greville Janner, citing 'clear public interest' over the adequacy of institutional responses to allegations against public figures. July 9 - Dame Lowell officially opens the inquiry. October 16 - Former child protection manager Peter McKelvie resigns from the inquiry's Victims' and Survivors Consultative Panel as it is revealed that he may face questioning over his own handling of pursuing allegations of child sex abuse. November 27 - Inquiry announces its first 12 investigations and Dame Lowell says she is committed to completing the in inquiry in five years. December 19 - Lord Janner dies aged 87. March 9, 2016 - Inquiry holds first hearing on the investigation into allegations against Lord Janner. August 4 - Dame Lowell writes to Home Secretary Amber Rudd to offer her resignation citing her career and family life. Advertisement

'Alexis Jay needs to swiftly bring about investigations and changes in practice so that more is done to prevent these horrific crimes.

'This inquiry has already faced a number of obstacles but we should never lose sight of those who are relying on it: abuse survivors and their families, current victims and those at risk of child abuse today.'

Former Tory children's minister Tim Loughton said: 'Glad Home Secretary has moved swiftly to appoint new child abuse inquiry chair - Alexis Jay did good work in Rotherham and is highly respected.'

Richard Scorer, specialist abuse lawyer at Slater and Gordon, said: 'Alexis Jay has a great track record of investigating abuse and is determined to get to the truth.'

Mr Vaz this afternoon welcomed Ms Jay to the post, adding she was 'clearly a suitable candidate with vast experience in these matters'.

He said: 'I hope it will be fourth time lucky as we must not let victims and survivors down.'

The senior Labour MP warned he still expected a full explanation from Dame Lowell for her sudden resignation and she has been invited to give evidence to MPs on September 6.

Alan Collins, one of the UK's leading experts in sexual abuse litigation from Hugh James, a law firm which represents survivors of sexual abuse who will be giving evidence to the inquiry, said: 'Having led the Rotherham abuse inquiry, Professor Jay has a deep appreciation for the needs of survivors, and should put those needs right at the heart of the inquiry's purpose.

'We represent a number of abuse survivors in the UK and overseas, some of whom will be giving evidence to this inquiry.

'They will be relieved that there will be no interruptions to the work that has already been undertaken.'

Insiders and lawyers in the wide-ranging inquiry, which is already besieged by setbacks, have accused Dame Lowell of acting in an 'autocratic' manner towards staff.

One insider told The Sunday Times she was 'difficult' to work with and staff had to develop a 'thick skin'.

Another told the paper: 'Goddard's treatment of the staff and of the panel of four assisting her has been autocratic.'

The source also claimed Dame Lowell had a poor memory, which was 'painfully obvious', while a senior QC added the former chair had become a 'laughing stock'.

The son of Lord Greville Janner revealed he had planned to take Dame Lowell to court, having criticised the 'disarray' of the independent inquiry.

Daniel Janner QC, the son of the Labour peer who died amid allegations of paedophilia, had sent an email detailing his plans just hours before Dame Lowell left her post last Thursday.

Justice Goddard, who admitted after her appointment that she was unfamiliar with British law, was selected by Mrs May in February last year.

In a statement following her resignation, the judge said she had found the job a 'struggle' and said she missed her 'beloved family' in New Zealand.

Announcing the resignation last week, the Home Secretary said: 'I can confirm that Dame Lowell Goddard wrote to me today to offer her resignation as chair of the independent inquiry into child sexual abuse and I have accepted.

'I want to assure everyone with an interest in the inquiry, particularly victims and survivors, that the work of the inquiry will continue without delay and a new chair will be appointed.

'I would like to thank Dame Lowell Goddard for the contribution she has made in setting up the inquiry so that it may continue to go about its vital work.'

Justice Goddard, who was appointed in April 2015, quit last week in the briefest of resignation letters that was sent to Ms Rudd.

She wrote: 'I regret to advise that I am offering my resign as chair of the independent inquiry into child sexual abuse, with immediate effect. I trust you will accept this decision.'

Baroness Butler-Sloss (left) and Dame Fiona Woolf (right) both stepped down from the role as head of the child sex abuse inquiry after concerns about their links to the establishment

Accepting the resignation, Ms Rudd replied: 'I know that this will have been a difficult decision for you to make, and something you will have carefully considered.

'I was sorry to receive your letter, but I accept your decision.'

Ms Rudd described the inquiry as the 'most ambitious public inquiry ever established in England and Wales' and praised Justice Goddard for her work.

'I know how personally committed you have been to ensuring that the inquiry is a success for those at its heart: the survivors and the victims,' Ms Rudd wrote.

'You have consistently demonstrated your desire to leave no stone unturned in order that the voices of those victims might be heard.

'It is a testament to your commitment that you have taken the difficult decision to stand down now, having set the inquiry firmly on course, and allow someone else to lead it through to the end.

'With regret, I agree that this the right decision.'

Home Secretary Amber Rudd today announced Ms Jay as the new inquiry chief promising she had a 'strong track record in uncovering the truth'