The Government has revealed that schools built by offsite specialist Caledonian Modular may not be able to withstand high winds or heavy snow loading.
Education minister Nick Gibb revealed concerns about structural integrity as a third school was officially closed in the growing crisis.
The latest school to be stricken with closure is Buckton Fields Primary School in Northampton.
The primary school, which was built by Caledonian Modular and has been open for two years, has now been told by the Department for Education that it cannot open for the new term.
School owner Preston Hedges Trust chief executive, Paul Watson, said: "We were naturally shocked to be told by the Department for Education that we were unable to use the school building at Buckton Fields at the start of this coming new school year."
In an interview with BBC Essex education minister Nick Gibb said that the DfE had carried out a review which had identified problems with the modular design of the schools.
"[The review] identified issues that related to the structural integrity of the buildings, weakening its ability for example to withstand extreme events such as high winds or a big snowfall or indeed a collision from a vehicle," he said.
Asked if the buildings could collapse because of extreme weather, such as a winter storm, Gibb said: "That's the risk and we are not prepared to take any risk with children, or teachers or staff's lives in a school, and that's why we intervened very quickly."
The latest primary school closure follows orders to stop two secondary schools from reopening for the new term.
These are Haygrove School in Bridgwater, Somerset and Sir Frederick Gibberd College in Harlow, Essex.
Both these secondary schools were built by Caledonian Modular in a single £38m batched deal under the Department for Education's £3bn modular framework, set up in 2020 to fastrack construction and deliver better value for money.
Two further primary schools in Cornwall only part-built as Caledonian Modular when it fell into administration in March 2022 were also completely demolished earlier this year.
At the time, the buildings were condemned after construction issues were uncovered at both Launceston and Newquay primary school projects.
