THOUSANDS of the region's school children could end up taking lessons in temporary classrooms throughout their entire education, it was revealed yesterday.

The multi-million pound cost of replacing hundreds of temporary classrooms now in use is likely to be prohibitively expensive in some areas.

Despite Government efforts to help local authorities reduce the total, the extent to which inroads can be made into the huge backlog is expected to be limited.

The scale of the problem has been highlighted in a report by North Yorkshire County Council, where the cost of replacing classrooms with permanent accommodation has been put at £47m.

More than half of the county's schools have at least one temporary classroom - and one has 13.

The oldest 20 date back to the 1960s, with 98 installed in the 1970s. As school numbers expanded in the 1990s, their numbers exploded further.

This does not include 50 prefabricated units put up just after the Second World War.

North Yorkshire County Council's director of education, Cynthia Welbourne, said: "Temporary classrooms are often used when the capital bidding system cannot be used to generate sufficient capital to provide permanent accommodation. Once on site, it then becomes very difficult to prove the case to the Department for the Education and Skills that the temporary buildings should be replaced by permanent ones."

Elaine Kay, principal officer with the National Union of Teachers (NUT) in the North-East, said temporary classrooms often left teachers and pupils feeling isolated.

"It's very difficult if a child has an accident or if a teacher faces disciplinary problems for them to communicate with the main building."

She said pupils also faced practical difficulties, such as going outside to reach the toilets and running water.

In Stockton, the borough has 57 temporary classrooms, but has a fraction of the number of schools in North Yorkshire.

In Middlesbrough, the number of temporary classrooms has been reduced to 20 thanks to substantial Government cash. The authority has a rolling programme which aims to replace them all.

Durham said it would cost about £8.5m to replace all of its 59 classrooms, but has a policy to replace them as soon as possible.