God does not "clutter up" explanations of how the universe began, the Archbishop of Canterbury has told Britain's most famous non-believer, Professor Richard Dawkins.

Dr Rowan Williams was speaking during a discussion between the pair at Oxford University on Thursday after Dawkins said he did not see why the archbishop would want to clutter up the explanation "with something so messy as a god".

Row ... Archbishop of Canterbury Dr Rowan Williams. Credit:AP

The archbishop said: "I don't see clutter coming into it at all, I'm not thinking of God as an extra who has to be shoehorned into it."

Dawkins said: "That's the way I see it."