Jeremy Corbyn has said "ministers must be questioned" over the fire at Grenfell Tower in London, after the Conservative government repeatedly delayed a report into new fire standards for housing.
The Labour leader told LBC: "If you deny local authorities the funding they need, then there is a price to pay that's paid by the lack of safety facilities all over the country.
"I think there needs to be some very searching questions asked as quickly as possible in the aftermath of this fire."
He later told Sky News: "Obviously ministers that ... received those reports must be questioned. But today every focus and every concentration must be on saving and protecting life."
Corbyn's statement follows criticism of Gavin Barwell, the former housing minister who is now Theresa May's chief of staff, for failing to push ahead with a review of tower block fire safety, which was repeatedly promised by the government.
Theresa May issued a statement promising that an "investigation will take place into the cause of the fire and if there are any lessons to be learned".
"Until then, our focus must be on ensuring that the emergency services have what they need to continue with their harrowing work, and that help and support is being provided to all those who have suffered as a result of this tragedy," the prime minister said.
Labour MP Rushanara Ali, who represents Bethnal Green and Bow and has been campaigning for higher housing standards for several years, told BuzzFeed News the lack of investment had created a time bomb thanks to "shoddy records of maintenance".
Ali was particularly angry at Barwell, adding: "The minister ignored it and he’s now working for Theresa May."
"I don’t think anyone knows what’s next," she said, warning of further problems to come. "The government has been so complacent about this. We’ve been fobbed off week in, week out. I’ve referred two housing associations to the regulator because I’m so worried about the risk to people’s lives. It’s a broader issue, not just about fire regulations – it’s about heaters falling on small children and roofs collapsing. It feels much more widespread.
"We're a Western, wealthy country – just look at us. This is just appalling."
Ali said the regulators for the sector were "toothless" and underfunded, leaving MPs trying to act despite having limited resources.
"The way to make sure these standards are maintained is proper inspections and regulations. In my experience even when you refer a provider to a regulator they just find ways around it. I’m still acting like the complaints department for [housing association] Clarion. MPs don’t have the capacity to deal with multimillion-pound companies."
"The government has reduced funding to the local authorities who protect social housing. They’ve done the same to housing associations."
She also directly criticised former Conservative mayor of London Boris Johnson for closing fire stations in London, even though there have yet to be any complaints over resources from the emergency services, who were on the scene within six minutes.
"We also need to look at what kind of support we give the fire services. Look at what’s happened with the police service and the pressure they’ve been under with the terrorist attack."