I am astonished that a C of E school is closing! What are they doing to fight your corner? Normally they try very hard to build schools up. Are you VA or VC?
Personally I would worry with a school the size of yours with 2 classes from R to Y6. I can see why people may not want it. Where I live, the village schools tend to be Infant only - except for a few C of E ones that have expanded to include a Junior department. However, sport, music and drama tend to be compromised and it is often older children who find it too insular and lack a wide circle of friends.
Is it that they could not find another C of E School to federate with? A clash of ethos maybe? Could you be the Infant school for a wider catchment area and another school be the Junior School? This has worked for a few village schools I know, but they are fairly close to each other. It was that or one had to close.
In truth, you have had years to build up numbers (sorry) and if you were once a lot bigger,then what has gone wrong? It is an ongoing aspect of rural school life that you have to make the school attractive to those out of catchment. It cannot close in August. Where would the children go?Has the Head and other staff been offered other jobs? Are they leaving? There is a full consultation period and I suggest you look up the legislation on this. I have never, personally, been in this position, but there are consultation periods and your County Councillor/Diocese should be involved. What do they know? I am also not sure of the position if it is a VA school. The Diocese would appear to have a big hand in this, so get their Education Officer in to speak to the governors and parents. What are the Governors saying about this? Are they being active at all?
Your strongest point is the new housing. Find out how many houses and projected number of children. Is the housing in your catchment? Try and get the Diocese to engage in providing an education for children from the new housing. I am at a loss to understand why they did not want to federate. It rather seems they want the school to close or they would be doing more to save it.