In a thinly-veiled attack on the Tony Blair era, when Alastair Campbell, the then communications director in Downing Street, said "we don't do God", Mr Alexander warned that people should have the courage to speak up for Christians without fear of causing offence.

Mr Alexander, the shadow foreign secretary, spoke out to voice his concerns about growing harassment and attacks suffered by Christians in the Middle East.

The poll, conducted for Prospect magazine asked "Should the Church of England and state continue to be connected?"

In 1957, 37% said it should separate with 37% saying should stay connected (26% didn't know). In 2013, 51% said church and state should separate with 27% saying it should remain connected (23% didn't know).

He added: 'For those early Christians it was a badge of shame.

'Today it is more commonly seen as a symbol of beauty to hang around your neck.

'As a friend of mine used to say, you might as well hang a tiny golden gallows or an electric chair around your neck.'

In a foreword to a book which will be published in the run-up to Lent next year, Archbishop Welby continued: 'Are we now living with a symbol emptied of power by time and fashion?

He ranged over the murderous attacks in Peshawar and Nairobi and the suffering and courage of Christians in Nigeria. He was surprised at the way the WCC meetings in Korea held together an extraordinary diversity of people united by the love of Jesus Christ. He announced that from January a Catholic order with an ecumenical and teaching vocation will be created, initially with four members, at Lambeth.