British Prime Minister Theresa May said on Thursday that initial tests on other high-rise buildings after the London fire tragedy have shown that the cladding was combustible.
May, made this known while citing the results of tests conducted after a fire killed at least 79 people in London.
Flames spread rapidly up the 24-storey residential tower block on June 17, trapping people inside, in what was Britain’s worst blaze since World War Two.
Exterior cladding added during a refurbishment may have played a part, residents have said.
The disaster heaped pressure on Prime Minister May, already fighting for her political survival after a snap election saw her party lose its parliamentary majority.
It has acted as a focal point for anger at government cuts to local authority funding and drawn accusations of criminal negligence.
“We should, of course, be careful on speculating what caused this fire, but as a precaution, the government has arranged to test cladding on all relevant tower blocks,” May told parliament.
“Shortly before I came to the chamber, I was informed that a number of these tests have come back as combustible.”
She said local authorities and fire services had been informed and were taking steps to make affected buildings safe and to inform residents.
May has launched a public inquiry into the fire and police have announced a criminal investigation.
May said tests on the cladding of Grenfell Tower where the fire blazed would be made public in the next 48 hours.
“This has been a wake-up call for the whole country,” said Jeremy Corbyn, leader of the opposition Labour Party.
“Residents of tower blocks all over the country are concerned, worried and frightened for their own safety. What we need is a step change in our attitude toward housing in this country.”
After apologising for a slow state response to the fire, May said it was right that the head of the local council had resigned.
Nicholas Holgate, chief executive of Kensington and Chelsea council, said he was forced out by the government.