Tens of thousands of children are being taught in crumbling old schools in the face of delays to public funding for new buildings, it was suggested on Wednesday.
Hundreds of schools, many of which are among the most dilapidated in the country, have applied to the government for money earmarked to fix those in the worst conditions, according to research by the Local Government Association (LGA).
But so far, none of the £2bn Priority Schools Building Programme funding has been allocated, despite an announcement due at the end of last year, it said.
The LGA is calling on the government to clarify which schools will receive funding, to allow plans to be made for the future.
The Department for Education (DfE) said it was assessing and reviewing every application, but did not give a figure for the number of schools that have applied for funding under the priority building programme, or say when decisions would be made.
The LGA said its research had found that at least 476 schools have said they are in dire need of new buildings.
This figure covers two-thirds of councils who are eligible to enter bids, and excludes academies, so the true figure could be higher, the LGA said.
It said there were concerns that if the scheme was heavily oversubscribed, then many schools in poor condition could miss out on funding, leaving youngsters in sub-standard buildings with leaky roofs, poor toilet facilities, inadequate kitchens and outdated security.
In Nottinghamshire alone, the county council has submitted an application covering 48 schools it believes are in an extremely poor condition, with a potential total rebuild cost of £176.6m.
And Sandwell Council has submitted an application for 17 schools, at a potential cost of £214m.
Councillor David Simmonds, chair of the LGA's children and young people board, said: "It's clear from these figures that government funding is not going to be able to stretch to cover all the schools that need it.
"The situation is now unacceptable and threatens to severely impact on our children's education.
"Schools can wait three months to repair a leaky roof if they know that at some point it will be fixed, but when that wait turns into six months, then 12 months or more, the delays become intolerable.
"In the current tough economic climate we know it's not going to be possible to rebuild every school from scratch and councils aren't asking for gold plated taps and state-of-the-art luxury staff rooms.
"But heads and parents are telling us that the condition of some schools is so bad it's getting in the way of providing a good education.
"Despite the hard work of teachers, the possibility that children could excel in such poor surroundings is a challenge too far."
Cllr Simmonds said schools were being left in limbo, and with councils suffering a 32% cut to their education budget, there was little room for them to step in and help.
Schools needed to know if they would get funding so alternative plans could be made, if necessary, to bring classrooms up to scratch, he added.
A DfE spokeswoman said: "There has been huge interest in the programme.
"We are carefully assessing and reviewing each application.
"We make no apologies for having a fair, thorough and rigorous bidding process.
"We are taking our time to get this right and will announce our decisions as soon as we can."
The priority building scheme to help schools in the worst conditions was set up after ministers controversially scrapped the £55bn Building Schools for the Future programme in 2010.
Under the move, hundreds of schools which were expecting to have their buildings refurbished or rebuilt, saw their plans scrapped.
Applications for the new scheme were due in by mid-October, with an announcement on which schools would be funded expected in December, the LGA said.
Shadow education secretary Stephen Twigg said: "The Priority School Building Programme has been repeatedly delayed - the Government should get on with it.
"As part of Labour's five point plans for jobs and growth we would prioritise these kinds of projects to create construction jobs and new primary school places.
"It doesn't help that the Government wasted precious time in dealing with this urgent crisis by chaotically cancelling the Building Schools for the Future, not commissioning a school condition survey for months and not meeting its own targets on the so-called priority programme."