At Christmas we lost an excellent deputy head. He moved to be a deputy at a larger school, motivated mainly by the higher salary but also a love of fresh challenges that had been crucial to his excellence as a senior manager. It seemed unwise to attempt replacing the irreplaceable in a hurry so an extended senior management team was proposed as a temporary measure for two terms.

Two years earlier a similar arrangement had existed when the head was seconded for year to be a industrial consultant. Three teachers who had been part of that arrangement still exercised whole-school responsibilities. They joined the head and the remaining deputy in the new team, supported by three new appointments.

Details of the whole-school responsibilities were published, people applied, interviews took place, three people were delighted to be selected and more than double that number exhibited varying degrees of anger and disappointment. As a mechanism for staff development such an arrangement is bound to be very beneficial for those involved. The additional payment of Pounds 750 a year is derisory, considering the extra work and responsibility.

But the number of people who applied, and the sense of grievance implanted in the rejected, testify to the rare opportunity it offered for substantial experience of whole-school responsibility.

Whether or not the experiment has been sufficiently successful for the school to exist permanently without a second deputy head has been rendered a moot question by this year’s budget crisis. If foreign language assistants are being discontinued to save Pounds 5,000 a year and if the postage book is being mulled over at length with much head scratching to see where savings can be made, then it becomes preposterous to even think of appointing a new deputy head at Pounds 28,000 a year.

There must be many other schools facing the same problem. They must be trying to reassure themselves about how beneficial such an extended management team can be for the school. A few people’s careers are given a great boost. If they move up and out, they can be replaced from the middle management level, thereby ensuring not only career development but, prior to departure, a broader awareness within middle management of whole-school issues and especially how intractable some of the problems can be.

If an extended senior management team is a temporary arrangement such advantages overwhelm any reservations. But what if such an arrangement becomes a permanent institution? Can even a relatively small (640 pupil) school function effectively without two deputy heads? There are, I think, three major disadvantages.

Those on the extended senior management team already have demanding jobs. One is head of a large subject department and four are heads of year. None seemed to be encumbered by masses of free time prior to promotion so what had had to be shelved to make room for the new role? If a significant number of academic and pastoral heads are distracted from their main jobs, what effect does that have on the efficiency of middle management, the level consistently identified by research as crucial to a school’s success?

Even in a time of budget crisis it may be possible to throw small sums of money (say, Pounds 750) at a job; it is nearly impossible to create more free time. The new senior managers will still teach the same number of lessons, putting themselves under great pressure. In addition, there will be only the head and one deputy who have the freedom from timetable constraints to deal with the crisis management endemic to all comprehensive schools.

That is one body too few to cope with irate parents, emergency budget meetings, potential new students or disruptive pupils who have leapt beyond an individual teacher’s tether and been sent to whatever the place of last resort.

My final reservation is perhaps one that would only become apparent after a few years of management by team. Most teachers accept that someone in a school has to make executive decisions.

However much participatory discussion has preceded such a decision there is generally a point at which the buck stops.

If the senior management team consists of people who have only a tangential connection to particular interest groups in the school - the head who teaches a few lessons of English, for instance, or the deputy who polices a couple of sink groups in maths - it is possible to accept decisions, even those you disagree with, as being dependent on whole-school criteria, rather than overly influenced by attachment to a particular clique.

Such trust would be more difficult to maintain if the decisionmakers included people whose working lives were still focused primarily on particular subject areas or year groupings in a school. Their objectivity would be questioned, frequently leading to an atmosphere of distrust, especially in those middle managers excluded from the inner circle.

In education, the Government is requiring people to do more with less. Teachers, being generally positive and purposeful people, are especially prone to excavate virtue from necessity.

Celebrating the obvious benefits of entrusting more jobs to able people is laudable. Ignoring the potential, long-term, vitiating effects of such over-extension on both individuals and the institution is myopic.

John Lancaster is a comprehensive school teacher in Cambridgeshire.