The extent to which government ministers failed to act on expert warnings about inadequate fire safety rules before the Grenfell Tower disaster in London can be revealed by the Observer.

As public outrage mounted and political pressure grew on Theresa May over the tragedy, former chief fire officer Ronnie King – who is secretary of the all-party parliamentary group on fire safety – said urgent requests for meetings with ministers and action to tighten rules were stonewalled.

King also revealed that ministers had failed to insist that life-saving sprinkler systems were mandatory in the design of new schools in England, despite clear recommendations in reports commissioned by the government itself, which advocated their use.

His criticism came as the prime minister admitted on Saturday that although the emergency services had been “heroic”, support for families of Grenfell Tower victims who needed help after the fire “was not good enough”.

King, who was a chief fire officer for 20 years, said: “They seem to need a disaster to change regulations, rather than evidence and experience. It was the same with the King’s Cross fire and the Bradford City football club fire. They always seem to need a significant loss of life before things are changed.”

He said that requests for meetings with former housing minister Gavin Barwell, now Theresa May’s chief of staff, were turned down. King said: “We have had replies, but the replies were to the effect that you have met my predecessor [the previous Tory housing minister Brandon Lewis] and there were a number of matters that we are looking at and we are still looking at it.

Theresa May’s Grenfell Tower statement: response ‘was not good enough’ Read more

“They are politicians and I am a professional fire adviser. I understand the difficulties they have with this,” King said. But he repeated: “They always seem to need a significant loss of life before things are changed.”

Reports into a previous fire at Lakanal House in Camberwell, south London in 2009, in which six people died, and a subsequent coroner’s report led to urgent calls from the fire sector for action. But seven years later those calls had still not been acted on and a long-awaited review of building and safety regulations had not even begun. In October last year Barwell answered a parliamentary question from the Labour MP Steven McCabe about the review timetable.

Barwell replied saying: “We have not set out any formal plans to review the building regulations as a whole, but we have publicly committed ourselves to reviewing part B [the regulations governing fire safety] following the Lakanal House fire.”

Another leading expert, David Sibert, fire safety officer to the Fire Brigades Union, who was told he would sit on the review, confirmed to the Observer that he had yet to be invited to contribute to it. It is believed that at most only a limited start was made and then abandoned as civil servants were directed on to other matters, notably the need to secure Brexit.

Last week Barwell declined to comment on when the review would be ready. Liberal Democrat peer Baroness Brinton, who also sits on the all-party group, said: “We could have had new regulations ready to go last year as the refurbishment work on Grenfell Tower was completed.”

On Monday MPs from Labour, Plaid Cymru, the Lib Dems and the SNP will turn up the pressure on government by asking urgent parliamentary questions to establish what work, if any, has been done on the review.

With the crisis threatening May’s already shaky hold on Downing Street, concerns about fire safety were widening to include regulations governing building of schools, student accommodation and care homes. King said: “The Department for Education have their own strict guidance for schools. Last July they issued their amended document as a final draft. Previously they said automatic fire sprinklers would be installed in all new schools except for a very few low-risk schools. They then issued revised guidance, which said that because of XYZ they are removing the requirement for sprinklers in all new schools.”

The Department for Education said that fire safety in schools was paramount but suggested sprinklers were not mandatory in all buildings. “All schools, like other public buildings, must adhere to stringent fire-safety legislation,” a spokeswoman said.

David Lammy, the MP for Tottenham, who knew one of the victims of the Grenfell Tower fire, demanded that the police seize all documents from relevant parties that could help explain its causes and assist the criminal investigations. He said: “The prime minister needs to act immediately to ensure that all evidence is protected so that everyone culpable for what happened at Grenfell Tower is held to account and feels the full force of the law. We need urgent action now to make sure all records and documents relating to the refurbishment and management of Grenfell Tower are protected.”

On Saturday police said that at least 58 people were missing and presumed to have died in the tragedy, and that the figure might increase. The latest official total includes the 30 who are already confirmed to have died in the fire. Commander Stuart Cundy said that the “significant” recovery operation might take weeks to complete. “As soon as we can, we will locate and recover loved ones,” he said.

On Saturday May chaired a government task force on the disaster from Downing Street. She later met victims and volunteers at a two-and-a-half hour meeting at No 10.

Downing Street announced that Britain would observe a minute’s silence at 11am on Monday to remember those affected. It will be marked at all government buildings, and other organisations have been encouraged to follow suit.

A £5m emergency fund will support the victims and a further £1.5m will pay for mental health support for the emergency services. Bereavement support will be provided to the families of those who have lost loved ones, those who have family members still missing or have been affected by the tragedy.

Writing in the Observer, Sadiq Khan, the London mayor, warns that similar blocks may have to be torn down in the wake of the disaster, as he attacks the response from the local council and the government. He said those affected had been “neglected by the authorities”.

“Residents and other local residents feel abandoned by those with the power: the council and government. They didn’t know where to go or what to do,” he writes. “Residents feel that they are neglected because they are poor. There has been a vacuum. It has exposed a gaping hole in how our government responds to events of this scale.”

He also asks whether deregulation has been to blame. “Those who mock health and safety, regulations and red tape need to take a hard look at the consequences of cutting these and ask themselves whether Grenfell Tower is a price worth paying. Nowadays, we would not dream of building towers to the standards of the 1970s, but their inhabitants still have to live with that legacy. It may well be the defining outcome of this tragedy that the worst mistakes of the 1960s and 1970s are systematically torn down.”

• This article was amended on 20 June 2017

