Joanna said in her article: ”I am standing on the roof of Bristol Cathedral with a seven-month pregnant woman.

”I am... cold - and rather confused by the fact I can see the top of Charles Kennedy’s head as he stands on College Green some way beneath us meeting local election campaigners.

”It’s a surreal moment, but we are up on the roof for a reason.

”Twenty-five-year-old Lizzie is up there checking the drains.

“It’s just part of her job as head verger — to ensure that the cathedral building is in good working order.

”Most people only have a vague idea what vergers do and that tends to be connected with their ceremonial roles when they wear the kind of black cassock I am modelling in the picture.

”But much of their work is very practical. And can include pulling dead rats from drains on the roof.”

She explained how vergers act as stage managers for the many events that take place in the church or cathedral in which they work, as well as being responsible for the cleaning, routine maintenance and security of the building. This can mean everything down to changing lightbulbs and a spot of gardening.

Lizzie is one of only four female head vergers in England and, at the time of her appointment in early 2003, she was the youngest head verger ever.

Her office is tucked inside the cathedral and contains a “Hogwarts-esque” stained glass window along with the usual office clutter of computers and bits of paper.

The verger’s original role, which was basically to escort important religious people through ceremonies carrying a ceremonial rod called a ‘virge’ (hence the name ‘verger’) which they occasionally used to hit people out of the way.

“I don’t batter people out of the way these days,” says Lizzie. “Although I think I am actually allowed to use it like that, under some ancient law,” she told Joanna.