The poem, “The Lesson”, tells of a teacher taking revenge on his unruly class by throttling, garrotting and hacking his students to death. He shoots one unfortunate in the head with a shotgun.

“The theme for today is violence,” the teacher says at the start of the poem and ends, as he waggles his finger at the dead, with the words: “Now let that be a lesson.”

Parents say they were appalled when they learned the poem was being studied by 14-year-olds, especially those of teenagers in one class who were asked to illustrate each verse with cartoons to visualise the scenes of violence.

“This is a sick and twisted way to run a classroom,” declared a Melbourne parent, Robert Wallace, whose son told him about studying the poem at school. “Had it been a student running amok in the teachers’ room I’m sure the poem would have been treated quite differently.”

The school his son attended later withdrew the book from its English course. After other parents protested to the Victorian education department, all school principals were told to review curriculum material being used in their schools. Principals were warned that what was being taught should be “appropriate for the students’ age group, including the students’ social and moral development”.

The president of the Free Speech Committee for Victoria, Terry Lane, said his group was dismayed by the ban on the poem. He described it as “the act of an illiterate numbskull”. “Only a person who has had a triple whimsy bypass could take offence at this funny little poem,” Mr Lane said. He said ordering the poem’s withdrawal was an affront to free speech at its most basic.

But many Australians are still in shock at the killing of 35 people, including two children, by a lone gunman at Tasmania’s Port Arthur earlier this year and do not want students to be confronted by tales of mass murder, even in jest or involving vengeful teachers.