By Justin Parkinson BBC News Online education staff

Parents are sending their children to school with body piercings in an effort to "take on authority", a teachers' leader has claimed.

Bob Carstairs, assistant general secretary of the Secondary Heads Association, said pupils were "trying to get away with more", putting staff under increased pressure.

His comments come after 12-year-old Rebecca Read was excluded from Oriel High School in Gorleston, Norfolk, for wearing a crystal tooth gem.

Mr Carstairs said: "Most schools would have done the same. But parents' attitudes have changed.

Discipline difficult

"Twenty years ago, if one was told their child was wearing something wrong, they would be mortified.

"These days, many parents try to rebel against authority. It makes it more difficult for the teacher, especially as society is more litigious, with more people ready to take legal action.

"There's a 'my daughter, right or wrong' attitude, which makes discipline very difficult."

School governors, who decide policy on clothing and jewellery, have to send a letter to parents of new pupils warning them of the rules.

If they fail to do this, they leave themselves open to legal challenges.

Rebecca Read's tooth gem caused her exclusion

Mr Carstairs said: "Over the last 10 to 20 years, fashions have become more outrageous. Body piercings and tattoos for youngsters have caught on.

"The emergence of the pop culture and grunge have increased the pace of change."

Often, if a child is wearing items against school rules, such as piercings, he or she is taught in a room separate from other pupils.

This is what happened to Rebecca Read before she was excluded.

Clash of authority

But, amid the growth in body piercing, there has been a counter-trend towards schools reinstating uniforms during the last decade.

Mr Carstairs said: "One of the good things about uniforms is that they do not allow wealthier pupils to dress in better clothes than poorer ones.

"There's more money about these days and pressure to spend more. Quite a few sixth-form pupils come in each day in a car.

"There's a much more competitive ethos among parents too, and sometimes the parents make their children compete.

"It's getting more difficult for teachers to hold the line. Whereas 20 years ago parents were more obedient to authority, it's now seen as fair game for their children to challenge it in any form."