Until the end of last term, Mike Arnold’s office was decorated with a stuffed snake slinking around two walls, and every chair occupied by teddies and other soft toys. The primary head wore socks depicting characters from The Simpsons and had a photograph of himself wearing a joke wig. But the good humour that characterised his leadership had been ebbing away for more than a year. Hence the “reminder to self” on the wall: “Do not snap at people.”

The pressure that comes with trying to turn around a troubled school or balance an inadequate budget is widely acknowledged. But fewer people are ready to accept that headship - even of a small, successful school - is intrinsically stressful. Mr Arnold, 52, not only recognises the problem, but this term he is implementing what he hopes will be a solution: he’s going back to the classroom for a year.

He has been head at Danbury Park community primary in Essex for 13 years.

The school is oversubscribed and has won two achievement awards. The small staff - only 11 teachers - is stable and harmonious.

But Mr Arnold has been unhappy for more than two years. In summer 2001, after an inspection found there were “no issues”, he began to feel dissatisfied. “It was more than the usual post-Ofsted slump,” he says. “I didn’t feel motivated. I’d been a head for 15 years and I wasn’t relishing the challenge any more.”

He had always spent time in the classroom, teaching or observing. And when, the following autumn, staff shortages meant he had to teach Year 5 for a term, he felt reinvigorated. “It was like a breath of fresh air. I put headship to one side and the school ran itself.”

After Christmas, though, with a new permanent teacher recruited, Mr Arnold was back in the headteacher’s chair, feeling bereft. That summer, he discussed with his wife Christine whether he should leave Danbury Park, education or headship. The holiday failed to refresh him. “I was as tense at the end as at the beginning,” he says. “For the first time in 29 years, I didn’t want to go back to school.”

The new term brought no obvious improvement. Mr Arnold wasn’t sleeping or eating properly, found it difficult to concentrate and at home was irritable and lethargic. Hanging over him was the memory of the headteacher to whom he had once been a deputy, who had had a nervous breakdown at 54 and never worked again.

He and his wife came up with an idea. Rather than leave the school he still “loved with a passion”, he would swap jobs for a year with his deputy, Sue Priestley. She would run the school while he reverted to classroom teaching. Mr Arnold took Mrs Priestley for lunch at the local pub in Danbury and “laid the whole plan before her”.

Mrs Priestley, who had been applying for headships, saw a useful springboard for herself and accepted. “He saw a problem, and he strove to find a solution to it,” she says. “Even though it’s a personal issue, he considered it as a whole-school package and came up with something that suited everybody.”

The next step was to talk over potential pitfalls with the chair of governors. Would he be a back-seat driver? Would parents accept Mrs Priestley as head? How would Mr Arnold cope in the staffroom? The governors met in January and after a three-hour session unanimously approved the plan.

While the proposed swap came as a surprise to staff, the news that MrArnold believed he was heading for a nervous breakdown did not. “All the staff knew there was a problem,” he says. “It wasn’t a figment of my imagination.”

Sue Priestley has been headteacher-in-training since spring, and took over the new role this term. The class Mike Arnold is teaching, Year 5 again, was her choice; she allocated the classes last term, and denied the outgoing head the history co-ordinator post he had his eye on. That went to a newly qualified teacher, Sarah Vickers, 22. “She’s fresh from college, it was her specialism and she’ll bring new ideas. Mike took it on the chin,” says Mrs Priestley.

Pupils have accepted the new set-up; some call the new head “Mrs Arnold”.

Staff found it harder, particularly in the transitional period last year, when some felt there was a leadership vacuum.

“The news didn’t surprise me,” says Deborah Ireland, 42, a Year 3 teacher in her seventh year at Danbury Park. “He hasn’t been the same Mike Arnold that I knew when I first came here. I hope the team will make him feel that there is a value in education, and that spark will be rekindled.” Newly qualified teacher Sarah Darker, 27, says: “If we can support him the way he’s supported us, it’ll be like giving something back.”

Mr Arnold and Mrs Priestley have worked together for 11 years at Danbury Park and feel they have the mutual trust necessary to make the project work. “I’ve promised Sue I won’t interfere,” says Mr Arnold. “She doesn’t have to come and ask me anything.”

They have worked as hawk and dove, says Sue Priestley, with her as the dove. She is finding her inner hawk, having had a summer holiday “cull” of the office teddies, removed the snake and replaced the Tottenham Hotspur screensaver. She intends to make her mark on the school during her temporary stewardship. “I want to develop the community aspect of our work more and improve professional development, but I’m not going to be the broom that sweeps clean the things that work and are valued. And they have to be things that are achievable in the year.”

While Mrs Priestley gets a pound;5,000 rise, Mr Arnold will take a pound;13,000 pay cut for a year. With his three children grown up, the money is not a big issue, he says. Because he is only 52, the impact on his pension will be minimal, providing he is fit to return. He hopes to resume his headship, but for now he sees himself as a class teacher.

“I’ve got to let go of it completely, otherwise I’m not going to reap the benefits of having a year out,” he says. “I’m going to give class teaching my best shot and hopefully sit down with governors in a year’s time with all my batteries recharged.”

Mr Arnold believes the Danbury Park experiment could be copied elsewhere.

Until he recognised the signs of burn-out, he was on track to spend 27 years as a headteacher if he remained in post until retirement at 60. But, he argues, few people can work at full capacity for that long.

“There may be other headteachers out there who feel that a year away from the pressures might enable them to extend their careers,” he says. “If the profession can find a way to allow senior managers to step away, then return refreshed, it could be a way of preventing the loss of headteachers.”

Wendy Wallace will return to Danbury Park school later in the year to find out how Mike Arnold and temporary headteacher Sue Priestley are faring in their new roles