The heads of Haverhill secondary schools Samuel Ward and Castle Manor also say, in an open letter, that the plan would result in "excessive disruption to learning".

Campaigners pushing Suffolk County Council to expand the middle school when it axes three-tier education have been left angry.

Jim Meikle, chairman of Clare and Local Area for Rural Education, said: "Heads and staff of other schools that will remain have been told not to discuss matters with the press; (this) should not be an exception."

The two headteachers, Howard Lay and Madeleine Vigar, support plans to send children from Clare and villages to Haverhill secondary schools from 11.

Their letter says: "We understand the wishes of some people in Clare for a separate secondary school but believe this would be a divisive step which would have a detrimental effect on the young people of the area by making it more difficult to deploy available resources effectively.

"There would be a considerable cost in closing Clare Middle School and the procedures for opening a new secondary school are complex.This could result in excessive disruption to learning."

The row comes during the county's consultation into the future shape of education around Haverhill – into which have been sucked children in Glemsford, Cavendish and Hartest.

Supporters of plans to turn Clare middle into a "rural community college" have been boosted by a groundswell of public support and the backing of MP Tim Yeo.

But confusion reigns over how much the project would cost.

A senior education officer told a meeting at Clare Middle School on Monday that it would be about £7m.

But a county spokesman told the Free Press this week that it could "range from £7m up to £25m".

He added: "It will depend on the specifications that come out of the consultation process. Sufficient financial work has been carried out by the county council to ensure all options being consulted on are affordable. Additional financial work is ongoing."

Special report in this week's Free Press