Councillors in Dorset have voted to scrap middle schools in Purbeck, which will result in the closure of four institutions.
Thirteen first schools will become primaries and another middle school will become a secondary at a cost of #163;36 million, officials have said.
Dorset County Council has been consulting on the changes for two years. Surplus places in the area run at 25 per cent and the council says schools will have a collective deficit of #163;1.2 million by 201213.
Director of children's services John Nash said the matter was "now urgent", adding that "the uncertainty caused by the situation is damaging the confidence of staff and parents".
Mr Nash told councillors there was a risk that the money needed to fund the reorganisation could be reduced because of public sector cuts, but said the "risk" of keeping surplus places was greater.
"There is a risk of a negative impact on standards as resources are stretched further to fund school places that are not being filled," he said. KM.