- Video report by ITV News political correspondent Paul Brand
At least 11 high-rise estates in eight local authority areas have been fitted with combustible cladding like that used on Grenfell Tower, the Government has announced.
Many more still yet to be checked in an urgent review following the blaze at the west London tower that killed at least 79 people.
Councils have been given until Monday to submit cladding samples for tests.
The number of towers found to be fitted with the same cladding is rising as more test results are returned.
At-risk buildings which have so far been identified are not being named until the landlords have had the opportunity to inform tenants, it added.
Downing Street earlier today said that some 600 building were thought to be wrapped in similar cladding to Grenfell.
However, the DCLG said that this was a misunderstanding and the figure related to all high buildings fitted with cladding, and not specifically to those thought to pose a fire risk.
Theresa May today urged social landlords to send samples as soon as possible, saying: "We cannot and will not ask people to live in unsafe homes."
She told the Commons up to 100 buildings can be tested a day with the results back "within hours".
Mrs May announced that a probe into whether cladding in Grenfell Tower met fire safety regulations will be published in the next 48 hours.
Camden Council today announced that cladding on its Chalcots estate was to be removed after tests raised concerns over its safety.
ITV News had previously revealed the block was fitted with the same cladding as on nearby Grenfell Tower.
A council spokesman maintained their cladding and insulation design "significantly differs to that at Grenfell Tower" but said the panels "were not to the standard that we had commissioned".
"Camden Council has decided it will immediately begin preparing to remove these external cladding panels from the five tower blocks on the Chalcots Estate," it added.
The chief executive of Kensington and Chelsea Council has resigned following a barrage of criticism over its response to the Grenfell disaster.
Nicholas Holgate said the communities and local government secretary had "required the leader of the council to seek my resignation".
He added he would have been a "distraction" if he had stayed in his post after the "heart-breaking tragedy".
The prime minister said it was right he had stepped down as "for too long residents have been overlooked and ignored".
Mrs May today declined to give the Conservative council leader Nicholas Paget-Brown her backing when asked if he should also step down.
"That is a matter that will be considered by the appropriate group on Kensington and Chelsea council," she replied.
The Prime Minister added a public inquiry had been set up, which will be chaired by a judge, to find out who is responsible and provide justice for the families.
"No stone will be left unturned in this inquiry, and for any guilty parties there will be nowhere to hide."
She further promised residents they would be re-homed within three weeks and that they would be looked after "irrespective of their immigration status".
"I would like to reassure people that we will not use this tragic incident as reason to carry out immigration checks on those involved, or on those providing vital information to help identify victims."
Mrs May told the Commons that more than 150 suitable homes had now been identified and were being checked in preparation for Grenfell survivors moving in over the summer.
"Nobody will be forced to move somewhere they don't want to go," she added.
Labour leader Jeremy Corbyn said Grenfell residents were "let down both in the immediate aftermath and so cruelly beforehand".
He said the public inquiry "must establish the extent and by who".
"At least 79 people are dead - it is both a tragedy and an outrage because every single one of those deaths could and should have been avoided".
Prior to the tragedy, Mr Corbyn said Grenfell residents had raised concerns about the safety in the block and believed only a "catastrophic event" would spur the council into doing anything about it.
He asked Mrs May why the political leaders of Kensington and Chelsea Council were not "taking responsibility as well for this whole dreadful event", following the resignation of the chief executive.
He said: "From Hillsborough, to the child sex abuse scandal, to Grenfell Tower - the pattern is consistent: working-class people's voices are ignored, their concerns dismissed by those in power.
"The Grenfell Tower residents and North Kensington community deserve answers and thousands and thousands of people living in tower blocks around the country need very urgent reassurance."
More than £700,000 has been paid out to victims so far, who will not be expected to repay the cash.
A central command centre has also been set up to control the response, with more than 600 people working to support victims in the area.