Referring generally to bullying and citing the German pastor Martin Niemöller, who led German Christian opposition to the Nazis, Dr John said: "In so many bad situations in the world and in the Church, too, we know what's happening is wrong but we keep our heads down and hope someone else will do the martyr bit and face down the bullies with the truth."

He quoted Niemöller’s famous warning that if Christians did not stand up for other groups being persecuted, when the time came there would be no one left to stand up for them.

"If you go to Jerusalem and visit Yad Vashem, the museum of the holocaust, you see the famous quotation in the entrance hall by Martin Niemoeller, the German pastor imprisoned by the Nazis. You've heard it before; but listen again:

At first they came for the Jews, but I didn't speak up because I wasn't a Jew. And then they came for the Communists, but I didn't speak up because I wasn't a Communist. And then they came for the gypsies and the Jehovah's Witnesses and the homosexuals and the handicapped and the mentally ill, but I didn't speak up because I was none of those things. Last of all they came for me. And there was no-one left to speak up for me."

Dr John recalled an anonymous school fellow from his childhood: "I have a memory from my schooldays that still haunts me. One year we had a boy in our class - I'll call him David. He was a pathetic kid, weedy and rather effeminate. And his life was hell. Children can be incredibly cruel to anyone who's different, and David was a brilliant target. He was beaten up, he got his lunch thrown away, he got called girl's names, nancy boy and poof and all the rest of it; and he always sat on his own. I can hardly think of the misery that kid must have gone through. Now I never beat him up, I never called him names; the fact it was happening used to churn my stomach. But I never said or did a thing to help him. Because of course I was terrified that if I did, they'd suspect me too, and I'd get the same treatment."

"And of course that's how it works, in so many bad situations in the world - and yes, in the Church too. We know what's happening is wrong, but we keep our heads down, and hope someone else will do the martyr bit and face down the bullies with the truth."

He said that clergy and churchgoers must be prepared to speak out on behalf of victims of injustice and for those who could not defend themselves. Dr John did not refer directly to the debate over homosexuality that has taken the Anglican Communion to the brink of schism, but the inference was clear.