The National Secular Society, formed in 1866, is a pressure group representing people who espouse no faith, and lobbies to keep public life secular.
Vice-president Terry Sanderson says it has 3,000 members in England.
Associate-members include former Labour Party leader Michael Foot, novelist Iain Banks, scientist Professor Richard Dawkins, playwright Harold Pinter, historian Dr David Starkey and journalist Sir Ludovic Kennedy.
Mr Sanderson said: "We are a pressure group which does not want to abolish religion, but get religion out of public life. We don't believe there should be bishops in the House of Lords, or Church schools.
"We want the separation of the Church and the State, but it's not just Christianity - it's to do with all religions."
