An Animal Liberation campaign with the tag line "Caged Eggs: Can't You Just Taste the Cruelty" has been rejected by RailCorp's advertising firm because it may upset children.

Animal Liberation's communications officer, Lynda Stoner, is angry but hardly surprised. "You can put anti-smoking ads with pus-filled lungs on the sides of buses, but we have to be shielded from anything to do with the food we eat," she says.

Two years ago there was a big row before Animal Liberation's barbed wire egg with the tag line "Laid in Hell" was shown on buses. Nothing as grim was planned this year. "We have shown very graphic images of battery hens in the past," Ms Stoner said.

"But this time we wanted to get the message across without people turning away. We wanted to make people think about what they're doing."

But a poster showing a cute family at breakfast that appears with a few sharp words about the life of caged layers was considered too tough by APN Outdoor, the company that markets RailCorp's advertising.

Ms Stoner says the company told Animal Liberation those details about beaks and legs "will distress children" and suggested "they tone down the wording to get approval".

Ms Stoner is not going to temper the message. "Why should we have to? If I temper it any more I'll be saying everything is hunky dory."

RailCorp backs APN Outdoor while holding out the possibility of an appeal. A spokeswoman, Marianne McCabe, said RailCorp "reserves the right to disallow certain advertisements at our own absolute discretion … This includes discretion to disallow any advertising that is political."

Commuters have recently been confronted by black-and-white billboards of caged bears stuck with tubes harvesting bile. On the concourses of City Circle stations this week are graphic warnings about ecstasy: "In thermal meltdown, your body literally cooks from the inside, muscles liquefy and vital organs collapse."

Ms McCabe explained that Government public health campaigns against smoking, melanoma and drug use were conducted under "other rules".

Ms Stoner is not mollified. "Those health ads are meant to shock and do shock."

She sees a double standard directed against Animal Liberation's message. "It's OK to put anything in the faces of the population to do with human beings but not with animals."

She thinks children can take it: "If they are old enough to read they are old enough to cope with reality."