There should be a “major national investigation” into the use of cladding on high-rise towers, Theresa May says.
It comes as it was revealed cladding from 95 towers in 32 local authority areas in England had failed fire safety tests – all of the samples submitted after the Grenfell Tower fire.
The probe could be a second phase of the public inquiry into the west London fire, the PM’s official spokesman said.
At least 79 people are feared to have been killed in the blaze on 14 June.
Earlier, an open letter to Mrs May from residents on the west London estate warned that the investigation of the fire must leave “no stone unturned”.
‘No stone unturned’
Before Grenfell, tower block fires in England were at an at least seven-year low, figures show.
According to newly released Home Office statistics, there were 714 fires in purpose-built blocks of 10 storeys or more in England in the 12 months to April – compared with 1,261 fires in 2009-10.
Of those high-rise fires last year, 56 spread further than the “room of origin” and three people died, compared with 12 fatalities in 2009-10.
In an open letter released on Tuesday morning, people who live at the Hurstway, Testerton, Barandon and Grenfell Walks on the Lancaster West estate said: “The investigation must leave no stone unturned.
“It must identify each and every individual and organisation who must bear responsibility and accountability for this tragedy and the mishandling of the aftermath.
“There must be swift recommendations to ensure there can be no chance of a repeat of this disaster elsewhere.
It said the bereaved families and survivors needed time to recover and grieve – “not least in view of the paucity of support they have been afforded by the state and its agencies in the immediate aftermath”.
The blaze, believed to have started in a fridge-freezer, destroyed 151 homes in the north Kensington block and in the surrounding area of the London Borough of Kensington and Chelsea.
The response to the fire has come under scrutiny.
Questions were raised about the cladding used on Grenfell in the immediate aftermath of the disaster and a nation-wide operation has taken place to identify and test buildings with similar cladding.
The firm that supplied Grenfell Tower’s cladding has ended global sales of the product for use in high-rise blocks.
But it is no “great surprise” samples have failed fire tests, director of the Centre for Window and Cladding Technology David Metcalfe said.
He said it was never “entirely clear” under the regulations whether or not the products used in cladding had to be of limited combustibility.
What a filler material consists of is not defined, he explained, and regulations do not say “specifically the cladding should be of limited combustibility”.
“Timber isn’t an insulation product, it’s not a filler material, so there’s nothing stopping you using timber on a high-rise building – but the government now are saying that all cladding should be of limited combustibility – there is a massive inconsistency there.”
The government had a new “strict interpretation” of the rules, he said.
The letter from residents, part of the Justice4Grenfell campaign, demanded their voices were “heard and fully included” in the inquiry into the blaze.
“We support the survivors and mourn the dead – they are our families, friends and neighbours, many of whom are still missing,” it said.
Mrs May ordered a full public inquiry into the fire the day after it happened.
The group said bereaved families and survivors should be given funding for legal representation in that probe.