If the plan goes ahead, Monkshouse Primary School would increase from a capacity of 315 pupils to 420.
The local education authority is responsible for ensuring there are enough school places available and Lincolnshire County Council believes Monkshouse needs to permanently be able to accept 60 children into its reception classes.
The published admission number (PAN) is 45, but the council asked the school to accept 60 into reception this academic year and will do so again next September.
The proposed implementation date for the PAN to rise to 60 permanently is September 2016.
The county council has pledged to provide additional classrooms, and extra group rooms, toilets, suitable outdoor hard play area and a larger school hall.
In a letter to all Monkshouse Primary School stakeholders, county council school organisation planning manager Matt Clayton said: “Spalding and the surrounding area will experience a shortage of available places if capacity at one or more of the local schools is not increased.”
Mr Clayton explained that an increased roll could lead to financial and educational benefits for the school.
“This may potentially provide the opportunity to enhance teaching provision and career opportunities for staff which, in turn, will benefit the learning experience of the children, he said. “An increase in the potential number on roll at the school to 420 will also enable the option of moving from the current mixed year group structure to one where all children are taught in single year group classes of 30 or less.”
The chairman of the school governors said it was a good move and would support the demand for primary school spaces in Spalding.
Simon Lilley added: “We are now one of the only primary schools in Spalding that is not two-form entry (60 per year) and the increased numbers, with proper financial backing and infrastructure, plus increased hall space that we have so desperately needed for some time now is very positive.
“All part of our journey, under the excellent guidance of our headteacher, Mrs Sue Goodsell, towards being an outstanding school.”
A consultation period on the proposal began this week and ends on Monday, November 10. Anyone wishing to comment should email firstname.lastname@example.org
If the proposal goes ahead, a planning application would be necessary, which would include consideration of additional parking and the impact on traffic.