Inserted in a magazine distributed by the Archdiocese of Liverpool, it was handed out to pupils, they claimed that “sophisticated activists” were trying to impose their “anti-God” views on children.
The front of the leaflet features a group of young boys and girls asking: “Am I a boy? Am I a girl? Or Both?”.
This is followed by a Biblical quote saying: "Male and female, he created them."
The Archdiocese of Liverpool has said the publisher of its magazine, Mersey Mirror, will apologise to schools for accidentally including the leaflet in magazine the Catholic Pic.
"An insert was inadvertently placed in the June edition of the Catholic Pic, the magazine of the Archdiocese of Liverpool, and in a number of Catholic publications across the country," a spokesman for the Archdiocese told The Independent in a statement. "It is normal procedure for such inserts to be sent to the publishers in advance for review, in this instance that did not happen.
"The content of the leaflet is not endorsed by the Archdiocese of Liverpool and it should not have appeared. In light of this incident procedures have been reviewed ensuring that all future inserts are checked prior to publication."
He added that they did not know how many schools the leaflet sent to and that an apology would be made in the next issue of the magazine.
The leaflets have also appeared in a number of other Catholic publications distributed to schools across the country,
The Northampton Diocese has also apologised for accidentally including the insert in their magazine.
The curriculum guidance, which has been updated for the first time in nearly two decades, expects secondary schools to teach students about LGBT+ content.
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