A new definition of Islamophobia will prevent criticism of the “hateful ideology of theocratic Islam,” say two of Britain’s leading atheists in new book of essays.

Richard Dawkins and Peter Tatchell - and other authors including a former member of extremist group Hizb ut-Tahrir - say attempts to define Islamophobia risk curtailing freedom of speech and work to expose extremism.

In a book of essays published today by the think tank Civitas, Mr Tatchell said he would have fallen foul of the new definition - proposed by leading politicians and backed by Labour - when he attacked Hizb ut-Tahrir over its anti-gay, anti-women comments.

“I was denounced as Islamophobic. But I was merely confronting the hateful ideology of theocratic Islamism, not Muslim people, the vast majority of whom do not subscribe to such murderous injunctions,” he said.

“My protest in 1994 could fall within the sweeping definition of Islamophobia proposed by the APPG, since it talks about Muslimness.

“No-one in our society should be discriminated against because of who they are, yet the term Islamophobia downgrades protecting Muslim people and mistakenly puts the focus on protecting ideas.