Jeremy Corbyn has declared the fire-risk tower blocks across England a "nationwide threat" and urged Theresa May to "get a grip and lead a national response".
The Labour leader questioned why the prime minister hadn't convened the Cobra emergency committee to coordinate the urgent testing and potential evacuation of residential buildings across the country that are known to have used cladding on their exteriors.
Downing Street said Corbyn was wrong – that there have been regular meetings of Cobra to coordinate the responses across government to the Grenfell Tower tragedy.
Corbyn himself was at the Glastonbury music festival in Somerset on Saturday, where he gave an address on the main stage declaring Labour's better-than-expected performance in the general election as evidence that politics in Britain is changing.
Addressing the Grenfell tragedy, Corbyn said: "Is it right that so many people are frightened of where they sleep, having seen what happened at the Grenfell tower?"
In a statement earlier in the afternoon, Corbyn said: "Tower blocks across the country have now failed fire safety tests in the wake of the Grenfell tower disaster. This is now a nationwide threat – and the prime minister needs to get a grip and lead a national response, including convening the Cobra committee to coordinate government and public action."
The statement was the first from the leader's office since the Labour-held Camden council told residents of the Chalcots estate, in north London, that they had to leave their homes on Friday night after the buildings failed safety inspections. At least 650 flats have been evacuated.
Some displaced people spent the night sleeping on air mattresses in community centres, while others were put into hotel rooms that the council was able to find at short notice. Other had to stay with family and friends. It may be three or four weeks before they can return to their homes.
He's arrived.....
Other evacuations may follow. According to the latest official figures, 27 residential high-rises across England have so far failed urgent tests ordered by the government after the Grenfell Tower fire killed 79 people.
As Labour councillors at the estate dealt with the fallout, Corbyn addressed the main stage at Glastonbury just after 4pm. Addressing the crowd, he spoke of achieving world peace and reducing economic inequality. "The commentariat got it wrong," he said. "The elites got it wrong. Politics is about the lives of all us."
In the crowd, there were cheers of "Oh, Jeremy Corbyn", which has been reverberating around the festival site.
Great meeting emergency service staff at #Glastonbury. At festivals, sporting events and in our communities they ar… https://t.co/KEyKrh2xFW
Corbyn, whose Islington North constituency is near the Chalcots estate, said he supported the decision of the Camden council to evacuate the buildings on the advice of fire experts.
The council – led by Georgia Gould, the daughter of one of Tony Blair's closest advisers – has been criticised by some for its handling of the situation, with some residents arguing that evacuation was unnecessary.
"The council has taken a difficult decision on the advice of fire safety experts, but the safety of residents must always come first," Corbyn said.
The Labour leader added: "I urge the government to make sure all necessary support – including, crucially, financial support – is urgently made available to councils across the country so they can deal swiftly and effectively with the scale of the fire safety challenge."
His criticism of the prime minister for not using the Cobra emergency committee to coordinate the testing and evacuation of high-rises nationally echoed that of Ed Miliband, his predecessor, earlier in the day.
1/ In 2007, on flooding, and foot and mouth, COBRA played a critical role. It is inexplicable to me that COBRA has not been convened...
2/ COBRA should be co-ordinating the process of cladding inspection, evacuation, management and rehousing...
3/That COBRA appears not to have even met suggests a total failure of grip at the heart of government.
Downing Street said Corbyn and Miliband were wrong to say Cobra hadn't been convened.
A government spokesman said: "Ever since the appalling tragedy at Grenfell Tower, the Government has been working very closely with local authorities, housing associations, and the private sector to ensure the safety of high-rise buildings. We are also in close touch with fire service and police.
"A cross-departmental task-force is coordinating this response, with regular meetings at COBRA chaired by senior ministers, including the prime minister."
May was in Liverpool, where she attended an event to celebrate Armed Forces Day.
In an interview with Sky News, the Conservative leader was asked about the evacuations in Camden and said: “Absolutely our first priority is safety.”
"What is needed to keep people safe is being done" says Prime Minister @theresa_may responding to the #Camden estat… https://t.co/Q30IBJFtcv
The government is working with Camden council to make sure that it “has the ability to do what is necessary to ensure that people have somewhere to stay,” May added.
The Liberal Democrats urged the government to declare a civil emergency.