The Keep Britain Tidy campaign should take its own advice and "bin the filth" by removing posters which use "offensive" sexual innuendo, campaigners said.
The posters - which use phrases including "trim my bush", "see the size of our Fanny's", and "Are you a dirty Chucker?" - were "offensive and inappropriate", the Plain English Campaign said.
Chrissie Maher, founder of the Plain English Campaign added: "As a woman, a grandmother and a tax-payer I am offended, disappointed and disgusted to find that such a worthy cause considers this language suitable for public information."
They are part of Keep Britain Tidy's "youth litter" campaign and are marked as appropriate for anyone over the age of 15.
The Keep Britain Tidy spokeswoman said: "The posters are specifically aimed at young people over the age of 18 and they aim to raise the issue of litter in a cheeky and humorous way.
"They have never been used as adverts and are only available to individuals who order them through Keep Britain Tidy.
"It is our responsibility to ensure that we are using the most effective methods to raise awareness of litter to people of all ages and we always base our actions on research.
"The posters are nearly 10 years old but remain popular today as their cult style and non-patronising tone can still deliver important messages about litter and society that is particularly relevant to a younger, but sophisticated audience."