Despite the success of a pilot scheme at Broughton and Newlands primaries,the Educational Institute of Scotland confirmed it is “taking advice” about the initiative. Ken Wimbor, the union’s assistant secretary, said: “The 1972 amendment to the 1956 Schools Code does seem to require all authorities to appoint a headteacher to all primary and secondary schools.”

Locally, the union backs efforts to improve management and lessen workload on classroom teachers, despite concerns about possible breaches of legislation. Borders has nevertheless concluded that in certain circumstances one head may be better than two. Two other pilots are believed to be in the pipeline.

Jock Houston, teachers’ representative on Borders education committee, said: “The union has been consulted and we have given it our blessing. We are all for radical ideas because we are conscious of the stress on headteachers who are teaching almost full-time. The fly in the ointment is that the council may be breaching legislation.”

Mr Houston said it was unclear whether two schools with one head could be classed as one school with two sites. In terms of legislation, that could be significant.

John Christie, the council’s director of education, said: “We sought advice at the beginning of the process and were told it was within the terms of the regulations.” Mr Christie added: “This is not saving us any money. It is cost-neutral.”

Broughton and Newlands are 10 miles apart and are sharing the one non-teaching head after the previous two heads retired last summer. Alistair Wilson, who is seconded from Morebattle primary, Kelso, tends to spend Monday and Tuesday mornings at the three-teacher Newlands and afternoons at four-teacher Broughton and reverses the pattern on Thursday and Friday. Wednesday is a “flexibility day”.

Mr Wilson said: “It is working very well and it allows me time and flexibility to do things. There is more time to write policies and for staff development. Parents were fully consulted.” The downside is the doubling of parent evenings and attendance at concerts and other school activities.

Borders has 71 primaries and more than 60 per cent are managed by heads with a teaching commitment. Responses to advertisements for heads of small rural primaries have been poor. It warns: “Headteachers of very small schools find themselves under pressure to cope with an increasing range of tasks to complete and no additional time in which to complete them. There are also problems of isolation and lack of senior management support.”

David Johnston, education convener of the Association of Head Teachers in Scotland, welcomed any initiative to reduce the administrative burden on classroom teachers. “Combining resources and budgets to share between schools is good administrative practice which could release heads. But teachers left minding the shop when the head is not there will still have to deal with phone calls and parents, ” Mr Johnston said.