By Justin Parkinson BBC News Online education staff at the NAHT conference

Budget troubles mean Sue Sayles has had to teach as well as lead

Admin, discipline, financial management, sometimes teaching: you name it, they seem to do it.

But even this hardy breed of professionals is feeling the pressure.

The National Association of Head Teachers says staff turnover is reaching "critical proportions", with the real prospect of shortages in the near future.

Changes

Over the next few years, heads have to face the full impact of the workload agreement.

This takes many mundane tasks, such as reading the register and photocopying, out of teachers' hands, and promises them free time for lesson planning and marking.

The number of complaints against staff has risen, in an increasingly litigious society, while budgets are stretched.

Meanwhile, exam league tables and school inspections publicly highlight heads' performances as never before.

I couldn't face another eight years of this before I retired Sue Sayles

Sue Sayles, a head teacher of 21 years' experience, is retiring from the job at the age of 52.

In the past year, she has had to teach a class herself for the first time, while juggling all the other pressures. It has become too much.

Ms Sayles, who has worked at the 174-pupil Riccall Primary, North Yorkshire, for 17 years, told BBC News Online: "I've been doing 75-hour weeks this year.

"The budget has meant I've had to teach in the classroom for the first time since I became a head.

"It's lovely to do it, but I can't do that and be a full-time head teacher.

"Last autumn, I was doing five days a week teaching a class of 23 children, aged seven to nine. It meant I was working evenings and weekends, missing lunch just to keep up with it.

"I worked in as well-organised a way as I could, but I had to start saying 'no' to people a lot.

"That's not fair on anyone. A head teacher should be available to deal with parents and whatever problems arise.

"I couldn't face another eight years of this before I retired."

Challenge

There were 21 applicants for Ms Sayles' job, of whom only three were deemed suitable for interview.

Luckily for the school, the candidate chosen was "excellent", in Ms Sayles' opinion.

But she said: "The new head will not teach. That's already been stipulated. So it means a school teaching staff of seven will effectively be cut to six.

"That means mixing up age groups and creating classes of up to 37 pupils. Those of different ages and, more importantly, at different curriculum stages, will have to study together.

"It will take a special kind of teacher to do that successfully."

Ms Sayles is to become the head teachers' equivalent of a management consultant, advising them how best to use their limited time.

She said: "It's been wonderful and I want to give something back. I'm not of retirement age yet anyway and I've still got to make a living.