A new teaching aid telling primary school children that terrorists kill people because they believe they are treated “unfairly” has been slammed by education campaigners.

Published just weeks before a suicide bomber attacked a concert in Manchester, killing 22 people including seven children, Talking About Terrorism recommends teachers “invite children to write a letter to a terrorist”.

The book, which contains forewords by NSPCC Chief Executive Peter Wanless and the director of the Jo Cox Foundation, describes terror incidents in which people launch indiscriminate attacks on members of the public as “a type of war”.

Terrorists kill people because they think they are being “treated unfairly and [are] not shown respect” according to the book, which goes on to give examples of “terrorists” it says were on the right side of history, including Nelson Mandela.

“The Suffragettes used violence and were called terrorists … Today many people think of them as brave women and admire their struggle for the right to vote,” it stated.

Published by Brilliant Publications, the book contains a foreword by Jo Cox Foundation director Iona Lawrence which impresses the importance of fostering “tolerance”.

Lawrence, who campaigns to bring illegal immigrants living in camps in France into Britain, warns that the world is “witnessing huge political and cultural shifts — one of these is the rise of extremism”.

Stating that “values and beliefs are shaped from the youngest age”, the foreword asserts the need for a “fairer, kinder and more tolerant world”, with Lawrence writing: “Children and young people can and should be equipped with the confidence to stand up for these values.”

But critics have slammed the book, which was written by Alison Jamieson and Jane Flint, as potentially dangerous.

Chairman of the Campaign for Real Education, Chris McGovern, said tasking children with writing a letter to terrorists could cause confusion and leave children upset.

“This a crackpot idea based on the misguided notion that primary school children must engage with, and show “respect” for, religious fanatics who are seeking to kill them,” he told the Express.

“It is part of the ‘British Values’ agenda that is being forced on schools by Ofsted and the educational establishment.

“The primary school classroom is not the place to humanise terrorism by ‘pretend dialogue’.”