Proposals to extend the age range at Gamlingay First School could see a split between counties.
The First School (GFS) governors have asked to join the Cambridgeshire based Comberton Academy Trust and hope to create a two tier education system, effectively breaking its links with Gamlingay Village College (GVC) and the Bedfordshire based Stratton Upper School.
But some parents fear this will put the Village College at risk and mean youngsters will have to go out of the village to school at age 11 rather than the current age 13.
Announcing a formal consulation, the First School governors said an increasing number of parents were opting for the two tier Cambridgeshire system, and moving their youngsters to neighbouring primary schools.
A loss of more than 20 pupils in the past two years had cost the school £60,000 in funding per year and the school roll was continuing to drop, down to around 175 this term.
In a letter to parents the governors of GFS said: “The impact of the fall in numbers is starting to make a real difference to the funding that we have available for teaching and learning and the way we structure classes. In September 2015 we will have to move from an eight class structure to a seven class structure..
“Without exception the families who leave GFS tell us that they are very happy with the education that GFS has provided for their children.
“They say that it has been a very difficult decision but that they want their childrren to have the opportunity to transfer, more easily, to a Cambridgeshire secondary school.”
But parents opposed to the plan, which will see GFS become a primary school, fear it will place the school in direct competition with the village’s middle school.
Campaigners fear it could force the closure of GVC: “resulting in the loss of excellent facilities at a time when the village is growing.
“A decision as important as this should be made by the whole community - not just the governors and parents at Gamlingay First School.”
They are urging people to write to GFS asking for the consultation to consider another option, to strengthen links with the Stratton Education Trust via GVC.
They are also asking people to write to Gamlingay Parish Council and MP Heidi Allen.
It could take up to two years for the GFS transition to take place with Year 4 pupils staying on at the school from September 2016 if plans to convert to an academy go ahead.