Channing’s headteacher donned the school’s famous brown uniform and went back to the classroom to live the hard life of a pupil for the day – while one lucky Year 5 student took over as headmistress.

The incoming head, Miss Uma Horder, 10, wasted no time in asserting her authority.

By 10.30am on her inaugural day in the office she had relaxed one of Channing’s uniform stipulations: hair was, for a day, allowed to be worn down, rather than tied up.

The reasoning behind Miss Horder’s decision was simple: “My friends like having their hair down and they asked me to change it.”

However, this was not before she had reprimanded some senior school pupils for their uniforms.

“Their skirts were too short and they were wearing necklaces,” she said.

The young headteacher was looking forward to touring the building site with some pupils (her friends) and said the best thing about the job was, “the power, you can do what you like”.

For the ousted ex-headmistress, Mrs Elliott, or Barbara, as she was now known, life was a little more difficult.

Her challenges began with the morning assembly at the junior school.

“I think sitting on the floor is all right when you’re seven, but it was distinctly challenging for someone of vintage years,” she said.

The tribulations did not stop there as she found a drama lesson with Year 7 “incredibly hard”, but nevertheless received a “good work” sticker, which she proudly displayed on her school jumper.

Like any good student, though, she had her excuse to get out of PE (physical education) already lined up.

“My dad sent a note in saying I can’t do PE because of the Saharan dust; I might be getting asthma,” she revealed.

The initiative, which raised £36,400, was part of the school’s Capital Challenge Appeal to contribute funds to Channing’s £13million plans for a new sports hall, sixth form centre, music school, and performing arts building.

The job swap idea was the brainchild of 15-year-old Olivia Howe, a pupil in Year 11.

The money raised more than tripled what Mrs Elliott had expected and has left her, and the school, delighted.