Watch Sam Blackledge's report
A school in mid-Devon is in such poor condition the Environment Agency says it poses a "risk to life".
Tiverton High School is in need of a multi-million pound overhall as its buildings are no longer fit for purpose.
The Environment Agency says it is not a safe place for children, with staff having to deal with regular water damage.
There are also regular incidents involving structures containing asbestos which get accidentally damaged.
Tiverton High School is now urging the Government to commit to funding a multi-million pound overhaul, saying the existing buildings are no longer fit for purpose.
The headteacher says a total rebuild would make a "massive difference" to staff and students.
The school sits on a flood plain on the banks of the River Exe.
Premises manager Jon Sowden said: "We've had children's work and textbooks damaged because of water, we have regular incidents in which asbestos-containing structures may be accidentally damaged.
"The Environment Agency says this is not a safe place for children to be. They say it is a risk to life."
Back in 2009, the school was told the previous Government would fund a total rebuild.
They even got planning permission and detailed designs - but the project fell apart.
Now, with the media's attention focused on the area ahead of the by-election, a group of parents are urging ministers to finally commit to the £40million overhaul.
Parent Adam Wishart said: "This is a good school, why can't we have the buildings that are fit for that kind of ambition?"
Head teacher Sammy Crook said: "We are a growing school, the demographic in the town is changing, big year groups are coming through, and we are having to be constantly creative about how we utilise the space available to us."
Tiverton and Honiton by-election candidates:
Jordan Donoghue-Morgan, Heritage Party
Andy Foan, Reform UK
Richard Foord, Liberal Democrats
Helen Hurford, Conservative and Unionist Party
Liz Pole, Labour Party
Frankie Rufolo, The For Britain Movement
Ben Walker, UK Independence Party (UKIP)
Gill Westcott, Green Party