Aluminium cladding should be immediately stripped off tower blocks, hospitals, schools and hundreds of other buildings, according to the National Housing Federation (NHF).
The body, which represents housing associations, said that testing had now proven that the cladding was unsafe and it should be stopped in favour of a national panel removal scheme.
David Orr, chief executive of NHF, said: “These tests were the right thing to do, but the results are now conclusive, aluminium composite material cladding simply does not pass these tests and is deemed unsafe.
“We are calling on government to halt the testing on ACM cladding and shift its focus to making people safe. It is highly likely that this means removing the cladding from hundreds of buildings we were assured were safe.
“This process has powerfully demonstrated a systemic failure in construction, manufacturing and the way that regulation has been applied.”
His call came as it was confirmed by Theresa May that 120 tower blocks in 37 English authorities had failed fire safety tests, and she said a “major national investigation” into the use of cladding on high-rise towers should be set up.
The BRE has been conducting the tests on behalf of the communities department to establish the flammability of external cladding on local authority tower blocks.
The tests are being carried out on buildings that are suspected of being clad with aluminium composite material (ACM) panels. ACM panels feature two thin aluminium skins sandwiching a cheaper core material that gives the panel its rigidity and keeps costs down.
The panels used for the external rainscreen on Grenfell Tower were a product called Reynobond, which features a plastic core.
The cladding has been tested on 120 blocks, and results so far show a 100% failure rate. Up to 600 blocks could be tested.
The test was devised by an independent panel of experts on behalf of the communities department and performed on the core of test samples after the external aluminium skin had been removed from the panel.
The test has three categories with a category 2 or 3 rating deemed by the expert panel to fail the combustibility standards in Part B, the building regulation covering fire.
Peter Bonfield, chief executive of the BRE, said the tests had been performed on ACM panels from a number of manufacturers and all had failed the test.
Hospitals and student halls have also been discovered with potentially flammable cladding with nine NHS hospitals at risk.
Emergency checks identified as many as 30 trusts with “category one” risks, meaning they have materials similar to those in Grenfell Tower or other unresolved fire safety concerns.
More than 17,000 care homes, hospices and private hospitals have been told to check their fire safety procedures.
Reviews are also being conducted by universities and private providers of flats used by students across Britain.
Newcastle University has confirmed that the privately run St James’ Point building, which opened two years ago, was fitted with the same flammable cladding. Bournemouth University and Edinburgh Napier University have said they had found similar types of cladding at student halls.
Nick Gibb, the schools minister, said that all school buildings taller than four storeys are being checked.