Some 27 high-rise buildings in 15 local authorities across the country have failed fire cladding safety tests in the wake of the Grenfell Tower disaster, the Department for Communities and Local Government (DCLG) has announced.
The revelation comes as more than 3,000 residents of the Chalcots Estate in Camden, north London, are facing weeks in temporary accommodation after four tower blocks were evacuated.
Portsmouth and Brent, along with Camden, Manchester, Plymouth and Hounslow, were named by the Government on Saturday as having buildings that had failed tests amid a nationwide safety operation launched after at least 79 people died when fire ripped through Grenfell Tower in north Kensington on June 14.
Camden Council leader Georgia Gould said around 600 flats have been evacuated due to concerns over "combustible" external cladding, insulation, gas pipes and fire doors.
But 83 households had refused to leave by Saturday morning.
Roger Evans, 51, who said he found out that his building was being cleared after a friend saw it on the news and alerted him by text, told the Press Association: "As far as I am concerned, nothing in that building has changed in the last few days, weeks, months or years."
"It was perfectly safe before, despite what they are saying now - I believe I am safe in there."
Iola McCarogher, 27, said: "I am not leaving, it is my home. Until someone comes and puts a court order in front of my face, I am not leaving.
"I have a disabled mother, I have animals in my property - they are not doing anything and no-one is telling us anything - it is ridiculous."
Ms Gould said it would "become a matter for the fire service" if residents stayed in their homes after being spoken to again by officials.
"Obviously last night was really distressing and difficult, having us knock on people's doors with no notice saying that they need to leave their flat," she said.
"Emotions were really high and some people, even with all the fire advice, decided to stay."
Ms Gould said it could take between two and four weeks to make safe the four buildings - Taplow, Burnham, Bray and Dorney - while residents of a fifth tower block, Blashford, were told they could return to their homes.
Work had been due to begin on stripping cladding from buildings on the Chalcots Estate, but Camden Council ordered the "decant" of residents on Friday evening following further checks by the London Fire Brigade.
People were told to leave as darkness began to fall, with some taking belongings in suitcases and carrier bags, and some locals saying they only learned of the evacuation as they watched the news.
Families with newborn babies and a Second World War veteran were among those ordered out of their homes after fire officers said they could not guarantee the safety of the buildings, with more than 100 staying in the Swiss Cottage Leisure Centre overnight and others sleeping in hotels.
Waiting for a minibus to take her family to a hotel six miles away, Zega Ghebre, 42, said the situation was "unbelievable".
She added: "The thing that makes me angry is that we watched the news, we tried to evacuate and they sent us back, they said they were only taking Taplow. We asked again and again and they gave us all different reasons. We were told 'There's nothing to worry about, you're not going to evacuate'.
"It's hard to trust anyone now, because if they come and tell me something, we won't know."
Ms Gould said the council is looking at accommodation including student halls and opening up newly built social housing, with hopes that by Monday 50% of tenants will be accommodated in the borough.
She said the cost to the council will be "really expensive" when taking into account the internal and external work on the blocks, and the temporary accommodation, adding: "But we are not thinking about counting the purse strings right now."
Refurbishment of the Chalcots Estate was overseen by Rydon, the company involved in the refit of Grenfell Tower, according to the Rydon website.
The site said the Chalcots project was a £66 million refurbishment which lasted 191 weeks.
The work included external thermal rain screen cladding on five towers, new aluminium thermally broken windows on five towers and an overhaul of external roofs
It added that 711 flats were modernised with new wiring, heating, kitchens and bathrooms.
Communities Secretary Sajid Javid told Sky News there would have to be a long-term review of safety regulations, stating: "That has to happen. In a country like ours, one of the richest countries in the world, in the 21st century, these kind of things absolutely should not be happening."
Birmingham City Council leader John Clancy told BBC Radio 4's Today programme: "This is actually a national emergency. The Government needs to accept it's a national emergency and it needs to focus on this.
"As each day has gone by since this crisis started, there seems to be less clarity. There is a collective national trauma at the moment and people up and down the country go to bed afraid."
Prime Minister Theresa May has said today that the Government is making sure Camden Council can do "what is necessary" to ensure people evacuated from blocks of flats have somewhere to stay, and work is done to make the buildings safe.