The government has agreed that two experts will sit with the judge investigating the Grenfell Tower fire, following pressure from campaigners.
They had called for a diverse panel to oversee proceedings, saying the inquiry risked being a “whitewash”.
Theresa May, who had earlier rejected calls for a panel, said the hearings would now have the “breadth of skills and diversity of expertise”.
The blaze in west London on 14 June last year killed 71 people.
The first phase of Judge Sir Martin Moore-Bick’s inquiry will start taking evidence on 21 May.
Up to now he had been helped by a legal team, civil servants and three assessors in reviewing and identifying documents and relevant material.
The hearings will examine the outbreak of the blaze and hear from firefighters, survivors and expert witnesses.
The new panel will join the second phase of the inquiry, which is not expected to begin until after December.
It will look at areas including the modifications made to Grenfell Tower before the fire, and the relationship between the different organisations responsible for safety, including Kensington and Chelsea Council.
‘Impartial and independent’
Survivors’ groups had been urging the prime minister to bring in a panel to help oversee the hearings.
More than 156,000 people signed a petition calling for individuals from a range of backgrounds to sit alongside Sir Martin.
The Grenfell United group, which represents survivors and the bereaved, said the change in the government’s stance had come about after lots of hard work.
It said it would mean the inquiry could “get to the truth of why our community was not listened to when we raised concerns”.
Adel Chaoui, the Grenfell United spokesman who lost four relatives, said survivors were “relieved” by the announcement.
“This panel means that the inquiry will have the expertise it needs to get to the truth of why our community was not listened to when we raised concerns, why such a dangerous refurbishment could be allowed to go ahead and all the issues that led up to that awful night,” he added.
Karim Mussilhy, who lost an uncle, said: “We’re disappointed that we’ve had to go through all of this to get the prime minister to listen. But she has listened and we thank her for taking our consideration seriously.”
Skills and expertise
Mrs May had previously rejected calls for additional panel members, although she said this could be reviewed.
Mrs May said she wanted the panel to be “relevant to the broad range of issues to be considered in phase two, and to best serve the increasing scale and complexity of the work going forwards”.
In a letter to Sir Martin, she said: “I hope this decision will provide reassurance to victims and the survivors of the fire, the local community, and members of Grenfell United, who have been clear… that you are the right person to lead this inquiry but who also believe that, in phase two, it would be beneficial to have additional panel members”.
Mrs May said she would write to Sir Martin again “once suitable panel members have been identified”.
The announcement came the day a group of people affected by the fire in North Kensington were invited to speak to Mrs May at Downing Street.
Among them was artist Damel Carayol, who lost his niece in the fire. He presented Mrs May with a print of his painting entitled Grenfell Tower: Eyesore!! Final Straw.
Downing Street said the print would be displayed in No 10.
MPs will also hold a debate about the Grenfell fire in the Commons on Monday.
The Labour MP for Kensington, Emma Dent Coad, said Parliament would debate the appointments and the inquiry and she planned to seek clarification on the way it would operate.
How the calls for an inquiry panel grew louder
29 June 2017: Retired Court of Appeal judge Sir Martin Moore-Bick is chosen to lead the public inquiry into the Grenfell Tower fire
7 July 2017: Sir Martin faces angry residents and survivors in a three-hour long meeting, amid calls for him to step down
15 August 2017: The terms of reference for the inquiry are published
14 September 2017: Sir Martin opens the inquiry, promising it will provide answers to how the disaster could have happened in 21st Century London – but faces criticism for refusing to appoint a survivor to an advisory panel that will consider the evidence with him
1 December 2017: Campaigners start petition calling for Theresa May to intervene in the inquiry and appoint a diverse panel
15 February 2018: Campaign group Justice 4 Grenfell drives three large billboards through London
22 February 2018: Grime star Stormzy uses his Brit performance to take a swipe at the prime minister over the government’s help for Grenfell. Downing Street emphasises the £58m it has committed to those affected
21 March 2018: Procedures for the inquiry are laid out at hearing in central London
11 May 2018: Theresa May agrees to appoint two experts to help oversee the second phase of the inquiry following pressure from victims’ families