The book industry believes that the scheme will improve sales of children's books and help it compete against DVDs and video games when adults are choosing gifts. The plan has been embraced by some publishers, including Puffin and Orion, who are already including a suggested age band on the back covers of books, unless the author has objected.
The scheme, run by the Publishers Association's Children's Book Group, was devised following research by Book Marketing Limited and the Arts Council England on expanding the book market. It showed that 53% of children's books are bought by adults, many of whom seek guidance on what books are suitable for a given age.
The result was the creation of an industry standard guidance scheme, which is printed on the back of books next to a barcode, and suggests the minimum age for which the book is suitable, such as "7+". Further research has shown that 86% of adults welcomed the scheme and that 40% said they were likely to buy more books with guidance ages.
However, the children's laureate, Michael Morpurgo, has told an audience at this year's book festival that it could be damaging to attempts to get children to read more.
He said: "There's just no such thing as an average seven year old. They could be four or 10 or, like me, 65. It's just nonsense. If you say a book is for a seven year old then the nine year old is going to be trying to cover it up at the back of the class."
His opinions are backed by 750 authors, including JK Rowling and Jacqueline Wilson, who have put their names to a 3,500-strong petition objecting to the move.
The decision as to which of the age brackets goes on the book lies with individual publishers. There are a choice of five -- 5+, 7+, 9+, 11+ and teen/13+.