On Sunday a couple of weeks ago, an extraordinary statement was read out in many churches in Britain. It had been prepared by the Catholic Bishops' Conference of England and Wales with the aim of fomenting protests to Members of Parliament.

Parishioners celebrating mass heard their priests tell them what scientists were apparently planning to do: "To create embryos that are half human, half animal."

They would use the egg of a woman and the sperm from an animal, the public was told.