There have been already been documentaries, films, and verbatim plays about the Grenfell disaster - a national tragedy born from a toxic blend of deregulation, profiteering, and embedded inquality.

Kentish Town writer Gillian Slovo with directors Phyllida Lloyd and Anthony Simpson-Pike have created an urgent, powerful, visceral account of what it was like to survive the fire that killed 72 residents in June 2017.

As the actors introduce themselves on Georgia Lowe's unadorned forum-style set, we're assured survivors gave consent for their interviews to be used, there will be no images of buildings on fire, and we can leave if we need to. But still their accounts of fleeing a burning tower block on crutches, or carrying terrified children down a smoke-filled staircase, are deeply upsetting.

Ham & High: Pearl Mackie as Natasha Elcock in Grenfell In The Words of Survivors.Pearl Mackie as Natasha Elcock in Grenfell In The Words of Survivors. (Image: Myah Jeffers)

Slovo forensically splices their emotional testimony with extracts from interviews, documents and the now closed Grenfell Inquiry. (Due to report next year.)

Here's David Cameron promising a bonfire of red tape; Eric Pickles' department ignoring coroners' advice after a fatal fire in a cladded Camberwell block; and the shifty execs of various companies capitalising on deregulation by flogging flammable materials to a wealthy borough keen to deliver the Grenfell refurb on the cheap.

Conscious of their duty of care in telling this story, Slovo and Lloyd give their subjects breathing space. The first half sees the terrific ensemble cast describe a happy melting pot London community of Italian, Portuguese, Syrian, Ethiopian and Caribbean heritage - many British born - sharing coffee on the stairwells while children play. Pearl Mackie's Waitrose worker Natasha Elcock didn't realise she was deprived until the media coverage afterwards.

Ham & High: Michael Shaeffer as Edward DaffarnMichael Shaeffer as Edward Daffarn (Image: Myah Jeffers) 

Problematically one of London's richest boroughs considers them and their block an inconvenient eyesore. The Grenfell Action Group's complaints about the renovation go unheeded, aren't they lucky to live 'for free' next to the wealthy Notting Hill set? Later a hijab-wearing resident is patronised by firefighters, and another dismissed by emergency call handlers because of his accent.

And why were riot police despatched on the night instead of a support team for traumatised survivors? Although London Fire Brigade is criticised for poor leadership and decision making, several survivors are rescued by firefighters who repeatedly return to the burning building.

Ham & High: Nahel Tzegai as Turufat YilmaNahel Tzegai as Turufat Yilma (Image: Myah Jeffers)

Each survivor has a box, used as podiums, seats and tables, until their true relevance is poignantly revealed. Towards the end, a screen slowly descends to watch filmed interviews with the real survivors, which stalls the dramatic momentum.

But then we're movingly involved in a call to action as the cast lead us silently onto the street and hand us Justice for Grenfell placards to plant.

Ham & High: Grenfell In The Words of Survivors runs at The National Theatre until August 26.Grenfell In The Words of Survivors runs at The National Theatre until August 26. (Image: Myah Jeffers)

Grenfell In The Words of Survivors runs at the National Theatre until August 26.