Prime Minister Rishi Sunak has rejected claims that as chancellor he denied funding to rebuild public buildings hit by crumbling concrete.

It comes after The Guardian reported that he blocked plans to rebuild five hospitals riddled with collapse-prone reinforced autoclaved aerated concrete (Raac) in 2020.

The paper said that only two of seven hospital rebuilding projects backed by the Department for Health were given Treasury approval in the 2020 spending review.

The NHS has been looking at the issue of Raac since 2019 and was funded with almost £700 million to mitigate Raac that it was finding in hospitals

But Mr Sunak said that such a suggestion was “not right” and ministers took the issue of Raac “very seriously”.

Speaking to broadcasters during a visit to Devon, he said: “The NHS has been looking at the issue of Raac since 2019 and was funded with almost £700 million to mitigate Raac that it was finding in hospitals.

“There are now seven hospitals that are in the new hospital programme, as new evidence came to light about the scale of Raac it was important to prioritise those hospitals.

“We made that decision earlier this year and on top of that other hospitals are being mitigated in line with the technical guidance and, as I said, backed by almost £700 million which was announced years ago.”

Health Secretary Steve Barclay had earlier said the claim was “inaccurate”, although he did appear to concede that the remaining five hospitals were only added to a rebuilding programme at a later stage.

The Government has said that the full extent of the Raac issues were unknown until an independent report by engineering consultants Mott MacDonald last year.

In fact, we were on this issue early, we were surveying hospitals from 2019 and we’ve been following the Institute for Structural Engineers’ advice, which is that not all Raac has to be replaced

“What Rishi Sunak as chancellor put in place was a £700 million fund for replacement – that was put in place from 2021,” Mr Barclay told Sky News.

“In fact, we were on this issue early, we were surveying hospitals from 2019 and we’ve been following the Institute for Structural Engineers’ advice, which is that not all Raac has to be replaced.

“What we need to do is monitor it, assess it, and where there is a concern with deterioration then it does need to be replaced.

“And that’s why a £700 million fund was put in place, two schemes for full replacement of those hospitals were agreed, but further work was then commissioned and a study from (Mott) MacDonald was then commissioned to assess the other five hospitals.

“Once we got that information, those schemes have then come into the programme – so a significant investment, specifically in Raac.”

A spokesman for the Government also said that the claims were “untrue”.

“The funding was not rejected by the Treasury, or the chancellor and chief secretary at the time, and there was an agreement to link these decisions into the wider New Hospitals Programme.”

Opposition parties have called for an explanation from the Prime Minister.

It is the latest funding decision to raise awkward questions for Mr Sunak, after he was accused of having declined a request for funding to rebuild more schools during his time in the Treasury.

Ministers remain under pressure over the issue of Raac, with concerns about the state of school buildings renewing scrutiny over the presence of the material in other public buildings and infrastructure.

The Lib Dems called the latest news a “disgrace”.

Health spokeswoman Daisy Cooper said: “The Prime Minister has put the public’s health and safety at risk for far too long.

“It’s outrageous that the Conservatives have actively ignored this issue for years.

“Rishi Sunak’s fingerprints are all over this concrete crisis.

“He must come to Parliament and explain why he blocked plans to rebuild crumbling hospitals, putting patients and staff at risk.”