Cal Hurst had a dilemma. She loved being headteacher of Greenwood junior school in Nottingham, but the long hours meant she didn’t get to see her own children as often as she would have liked. On maternity leave after twins Gabriel and Seamus had become the fourth and fifth additions to the Hurst brood, Cal started to wonder how she was going to cope with a high-pressure job and a hectic home life. Something had to give. One way of combining the joys of bringing up children with a fulfilling career is to job-share. But job-sharing headteachers were virtually unheard of. Besides, who could she work with?

She was still thinking about it when her husband, Les, came home from his job as headteacher of the local primary. The two of them began mulling it over, thinking of possible candidates. Then they had an idea: why not do it together? “A chill went down my spine,” recalls Les. Initially, the prospect of leaving Lantern Lane, the primary school in East Leake, Leicestershire, where he had been head for 18 years, filled him with dread.

He had “the best job in the world”; why would he want to leave? But the more they talked about it, the more it seemed to make sense.

“When you have five kids under 12, you have to be there for them,” says Les. “We decided the way forward for us as a family was that one of us needed to be at home. We had to make that commitment.”

Cal explained her plan to her governors, who “quickly came round to the idea”, and her post was duly advertised as a job-share. Even then, there was no guarantee that Les would be selected. Nine people requested application packs, but Les’s was the only one returned. He was interviewed and heard just before Christmas that he had got the job. “I shall be upset to leave; it’s a dreadful wrench,” he says. “But I don’t want to go to my grave thinking, ‘what if?’ ” Cal went back to work in January, to serve her final term as sole headteacher, and she and Les started working together this week. “I am going to share this job, not relinquish part of it,” she says. “It’s a major, major life change for Les and for me. But it’s an exciting change.

In some ways being a headteacher is quite a lonely job: going through processes of consultation, making decisions and so on. If you have another person you can sound those things out with, that has got to be positive.”

Cal and Les have worked together before; he was her boss when she was a class teacher at Lantern Lane in the early 1990s. “One of the three best teachers I have ever worked with,” he says. “We have very different skills that plait together nicely. Call mine experience and hers raw talent.”

Having a married couple in charge at Greenwood won’t be a problem, says Cal. After all, half the partnership is already well known to staff and pupils. “I have staff employed on a job-share basis and there is sometimes an issue about who goes to staff development and that kind of thing. If you are a couple who live together the issues aren’t going to be there. We are both headteachers anyway, so most of our evenings are geared around work.

We think the same way, and now we are going to be working with the same goals in mind.”

But any fears that their personal partnership might get in the way of their professional performance are misplaced, Les believes. “Obviously there will be times when we disagree, but we will do our arguing at home.” Pooling the talents of one headteacher of 18 years’ standing with another described by Ofsted as “a good organiser with a great capacity for work” has to represent value for money for the school.

But for the Hurst family, while the rewards will be great in other areas, their family income is about to be halved at a stroke. “That’s the only negative, that you are one headteacher’s salary down,” says Les. “We could both go to work and bring home pound;100,000 a year and have somebody come in and look after the children. But there comes a point where you think, ‘this isn’t worth it’.”

While this represents a new departure for Cal and Les, they are not the first couple to have embarked on a joint headship. And Greenwood junior school has something of a record. Until three years ago, Patrick Fielding and Sarah Blamey shared the post of deputy head, with Cal as the other deputy. Then Cal was promoted and Patrick and Sarah moved on to become joint heads of Mayflower school in Leicester, the first married couple in the state sector to do so.

“We had established a way of working together so it wasn’t anything new for us,” says Sarah. “But we moved into a new situation where people didn’t know us. At Greenwood the staff knew us and knew how we worked. At Mayflower they were brave taking us on as a job-share - it was unheard of.”

They split the working week, taking it in turns to work three days one week and two days the next. Sarah always does Mondays and Tuesdays, Pat’s in on Thursdays and Fridays and they work alternate Wednesdays, ensuring that one of them is always at home to take care of their children Eleanor, seven, and Hannah, five. “We were both keen to bring up our children and it seemed the ideal route,” says Sarah.

Sarah, 39, and Patrick, 38, met at university 20 years ago, and their careers have followed similar paths. They have worked in the same schools since 1991, and they trained to be headteachers and external advisers together. “We have similar experiences and understanding of education,” says Patrick. When they decided to look for a headship, they sounded out various education authorities, and, after a favourable but unsuccessful application to a school in Bristol, the Mayflower job came up.

“No one had tried it before; we were moving into unknown territory,” says Patrick. “It was difficult to know how to go about it so we submitted individual CVs and joint letters of application, but we were interviewed separately. We had to prove we were each capable of leading and managing the school as an individual.”

Mayflower, a large primary about two miles from Leicester city centre, serves a predominantly Asian community, and 91 per cent of the 411 pupils speak English as an additional language. Inside the neat and tidy post-war buildings, there are few clues that this is a school with two heads apart from the repeated picture captions under their staff photographs. Displayed nearby are two achievement awards - not one for each head, but successive accolades for improvements in pupil attainment. Mayflower came 40th in this year’s national value-added tables.

Patrick and Sarah are quick to praise the “wonderful” staff and parents, as well as their pupils, for the achievement. “They are very responsive children from aspirational families; their parents are supportive and that has a massive impact,” says Patrick. “Having more than one head is outside people’s experience and I expected more questions from parents,” says Sarah. “But they have been supportive from day one.” Ofsted said “they work very effectively together”, and they have to. School inspectors also noticed the “well thought-out” school plan covering one wall of their shared office.

Constant communication is the key to their success. A logbook is filled with the minutiae of the day’s happenings and taken home for evening debriefing sessions on everything from minor accidents to major building work. Their dual identity has caused some confusion among builders working on the new nursery classroom - one couldn’t understand how the headteacher he’d been dealing with the day before had suddenly changed into a woman.

“We probably put in more hours than one person,” says Sarah. “We are always thinking around things. But we are prepared to do those sorts of things because of the opportunity to work in this way.”

The division of labour, in home as in school, is pretty equal. Because of the way they divide their working week, Patrick is always there for the leadership team meetings and Sarah chairs the staff meetings. The remaining school management duties are split down the middle. “The way Pat approaches a situation can be completely different to the way I would,” says Sarah, “and that makes you reflect on your own way of doing things. It’s professional development every minute of every day.”

“The most important thing is that we share a vision of where we want to be,” says Patrick. “If you share that, whatever you hit along the way, you tend to make the same decision.”

Now that both their children are at school full time, Patrick and Sarah have more time to devote to other interests; he is a successful composer of soundtrack music and she is involved in work on the national primary strategy. They get enough of a break from the job to return refreshed the following week. Unlike couples who work together in the conventional sense, they don’t spend all day in the same place, so it doesn’t get claustrophobic.

“On a personal level it’s very powerful to understand fully what it’s like at work and at home,” says Sarah. “If you are at work full-time you tend to think your partner’s got it easy being at home. We see both worlds.”

“Being a headteacher is a bit like being manager of a football club,” says Pat. “You are an important figure in the organisation. We all have egos, and some people won’t accommodate a second person. It all depends on your personality if you can handle someone else.”

Cal and Les Hurst are about to embark on a life change that will combine the familiar - doing a job they know so well and with the person they know best in the world - with the new experience of sharing the role of school leader and, stranger still, having two-and-a-half days a week off work. It is a perfect solution for people in their position.

“There are many good, ambitious teachers who we need to keep in education who will be lost if they can’t keep a better work-life balance,” says Cal.

“We have always shared the household tasks and everything that goes with that, so there won’t be any issues for the children having Daddy at home.”

Their 12-year-old son, Sam, is at secondary school now, but their daughters, Sally nine, and Eilish, six, are still pupils at Lantern Lane.

They are sad to see their father leave the school, even if it means they’ll see more of him at home. But Cal foresees an unexpected consolation.

“Perhaps one of them will finally get to be Mary in the school nativity play,” she laughs. “No one dares pick them at the moment.”