The brawl between Mary and Joseph started quietly. As adoring parents looked on, the two six-year-olds tried to wrestle Jesus from each other’s arms.

By the end Mary had gained possession of the doll and was pinning Joseph to the floor with the manger.

The fight is a highlight of a programme exploring how nativity plays can go wrong, which the BBC will broadcast on Christmas Eve.

Producers of “I Want to Be Mary” put a call out in the summer for videos showing unusual moments from festive productions in primary schools.

Teachers and families sent in more than 300 tapes, leaving researchers to sift through hours of off-key renditions of “Silent Night” and “O Little Town of Bethlehem”.

From the clips selected, it seems that the most frequent nativity play accident is children dropping or throwing the Christ-child - usually at a crucial moment. Shepherds who use their crooks as weapons, angels who pick their noses, and wise men who fall over are also common.

Amara and Harry, a pair of five-year-olds from Birmingham, are shown discussing how an accident with Jesus undermined their performances as Mary and Joseph. (“He was a good Joseph, except he dropped the baby,” Amara says, accusingly.) Julie Aberdein, the programme’s producer, said that watching the unedited videos had often been tedious but it had left her feeling festive.

“You realise that teachers are amazingly patient,” she said.

“It was also fascinating seeing how schools have updated the nativity play.

They’ve been a feature of Christmas since the 12th century, yet some schools will put in pop songs like ‘Barbie girl’.”

The programme comes at a time when several Edinburgh schools have banned video cameras from nativity plays, fearing the tapes might infringe pupils’ civil liberties or fall into the hands of paedophiles.

Ms Aberdein said her team at BBC Manchester had been careful to get permission from all parties involved before using any of the clips and would not be broadcasting the full names of pupils or schools.

Teachers have also been recounting their Christmas play nightmares in The TES’s online staffroom. Shepherds with unfortunate itches and incontinent angels are cited as distractions to the festive tableaux.

One teacher recalled a recent nativity play at a Durham primary school where the children had been encouraged to improvise. Mary, aged nine, greeted Joseph with the words: “Eeeh Joseph, am I glad to see ye. Our Jesus’s been a little bugger all day.”

Another voice 16 Ted Wragg 52

“I Want to Be Mary” will be broadcast on BBC1 on December 24 at 5.15pm