Jacksdale Primary & Nursery School, Main Road, has been using the temporary building for foundation pupils for several years.
However, planning permission for the building is due to expire and the council, the local education authority, has lodged an application to keep it in its current form.
This, the authority says, will ensure there will be no shortage of early years places, if the classroom ceases to exist.
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Papers submitted to its own planning department confirm it has 52 pupils registered to use the foundation unit.
These children, aged two-four, make up almost 55 per cent of the 95 children in total who require foundation school provision across Jacksdale ward – a further 40 attend Westwood Infant and Nursery School, while there are two childminders supporting three children.
However, the council states there are currently no vacant places for children aged two-four in Jacksdale ward, with the retention of the classroom necessary to ensure 52 places are not lost.
The council said: “Early years providers report they share their vacancies with Early Childhood Services on a regular basis.
“The latest information informs us there are zero vacant places for two, three and four-year-olds to access their early years entitlement in Jacksdale ward.
“If the foundation unit at Jacksdale School was unable to operate in the future, we would see a sufficiency issue within the ward. The number of vacant places at present indicates there would be a deficit of 52 early years places.”
The council adds the existing building provides affordable childcare to support families to ‘work, or train to maximise work opportunities’, which helps raise household income and improve outcomes for children.
It states children in workless families are ‘three times as likely to be in relative poverty’ than families where at least one parent works.
And it says the foundation unit offers flexible and accessible education for both families and children, while also improving pupils’ cognitive and emotional development between foundation and school years.
Under the planning proposals, which are expected to be reviewed by council officers in the coming months, no changes would be made to the existing temporary building at the Main Road school.