Education Minister Nick Gibb insists the specific crisis will be resolved before Christmas

The specific crisis facing schools must be resolved “well before Christmas,” a minister said on Tuesday as he defended both Rishi Sunak and Education Minister Gillian Keegan over the scandal.

The Prime Minister chaired his first Cabinet meeting after the summer recess and was faced with a growing list of political issues, including the economy and cross-Channel migrants.

The two upcoming by-elections will be a tough test for the Conservatives, and the issue of RAAC (aerated concrete) has suddenly found itself at the top of the agenda.

Schools Secretary Nick Gibb denied that Mr Sunak had neglected children's safety during his time as Chancellor of the Exchequer by refusing to rebuild more schools.

While he acknowledged that Jonathan Slater, the former most senior official at the Department for Education, was correct in saying that Mr Sunak had only approved funding for 50 school remodeling projects each year from 2020, he insisted this was in line with previous years.

“I asked officials about this yesterday and we can find no evidence of it,” he said after Mr Slater said officials had asked for 300 to 400 schools to be rebuilt or repaired, adding that no department had ever gotten everything it wanted from the Treasury.

Mr Gibb also rejected claims by National Audit Office director Gareth Davies that the Government had taken a “band-aid approach” to maintaining key schools.

The minister told Sky News: “We spend £1.8 billion a year… and we are more proactive about this than any other government in the world.”

Emergency measures have already been taken at 52 of the 156 schools where the concrete was found to be crumbling. Children there are expected to be out of school for an average of six days, Gibb said.

“I expect the same thing will happen in the remaining 104 schools,” he told LBC, “and I suspect it will all be sorted out much sooner than Christmas.”

Ms Keegan's position was questioned by some Conservative MPs after she was caught on a hot mic apparently complaining that she was not being given more credit for her fight to resolve the RAAC issue.

Questions were also raised about why she remained on holiday in Spain in the last week of August, despite authorities deciding that RAAC in schools posed a greater risk than previously thought, abruptly throwing the start of the new school year into confusion for many children and parents.

Mr Gibb said his boss had apologised for her spontaneous outburst and that she had expressed her “frustration” at the ITV reporter's questions “when the department and the public service have worked so hard to protect our children and keep our schools safe”.

Ninety-five percent of the approximately 24,000 schools in England have responded to questionnaires indicating whether their buildings have RAAC. “We have asked for these questionnaires several times. What frustrates us is that we want the remaining five percent to respond,” the minister said.

The Ministry of Education has given schools a deadline of Friday to respond, but will publish a list of all affected schools later this week, he said.

Labour shadow minister Jonathan Ashworth accused the government of running “total chaos” and told Sky: “You asked for more investment in schools and Rishi Sunak cut it.”

But a day after Sir Keir Starmer reshuffled his shadow cabinet ahead of next year's general election, Mr Ashworth refused to give further details on whether the Labour Party would launch a more ambitious school renovation programme if it won power.

The RAAC problem is not limited to schools; hospitals and courthouses are also being investigated.

Britain's chief inspector of prisons, Charlie Taylor, said it would be “extremely worrying” if the weaker concrete was found in prison buildings, as space is already at a premium and cordoning off parts of them is “not an option”.

“The normal response in prison would be to close some wings of the prison, restart operations and get everything running smoothly again,” he told Times Radio.

“But at the moment that's just not an option because there isn't enough space in the prisons to carry out the remedial work that would be necessary in a prison that has sunk into such chaos.”