They may be as alike as chalk and cheese, but Belinda William and Dawn Mayson believe they are a winning combination.

The two share the headship of Stoughton infants in Guildford, Surrey. One is in control on Mondays and Tuesdays, the other on Thursdays and Fridays, and on Wednesdays they are both in harness.

Part of the reason they can work together in this way is that they are sharply contrasting characters. Ms William, a jovial blonde, calls herself “the risk-taker” while Ms Mayson, a more cautious brunette, is the “risk-assessor”. (When a photographer from The TES clambered up wall-bars in the gym to get a good picture, Ms William egged him on while Ms Mayson suggested he sign a waiver in case he injured himself.) “Belinda is the blue-skies thinker,” said Ms Mayson. “I’m the one with my feet on the ground. She comes up with delightful ideas for extra-curricular activities and I have to remind her of the practical side.”

Among Ms William’s schemes has been Wonderful Wednesday - an occasional off-curriculum day aimed at spiritual development - which has included African and Indian dancing.

The school decided to try the job-share after its previous head handed in her notice in the summer. Staff were confident that a replacement would be found swiftly. The small school is in a deprived corner of the town, but it received an excellent report from inspectors this year, and its test results are well above average. Yet three job advertisements failed to attract a single suitable candidate.

Ms Mayson and Ms William, both senior teachers at that time, were reluctant to apply for the top job as they had young families. The two friends, who had taught at Stoughton for more than 15 years, were also loath to give up their classroom teaching. But as the search for a head grew desperate, the pair suggested to governors that they could share the headship.

Their job-share is distinctive because on days when they are not in the office, they return to teaching their own classes. Two other teachers, who also job-share, then take the pupils on the days when Ms William and Ms Mayson are occupied with headship.

“The parents have been positive and the pupils have not been confused,” said Ms Mayson. “It was probably easier than if we had a new head - we are familiar faces.

“The biggest challenges were at the beginning. For example, staff would ask one of us questions and then go to the other head as well. It’s also been hard to switch off being head on teaching days. It’s something we’ve had to learn.”

The difficulty in finding a new head is typical. A survey published in October by the National Association of Head Teachers and the Secondary Heads Association revealed that half of primaries receive five or fewer applications for headteacher posts.

The joint heads recommend their approach and say they would miss the company if they became heads on their own.

“Being a head can be lonely,” said Ms William. “But I can talk to Dawn about any doubts I have.”