Comparing provisions in the UK’s revised human fertility law to Nazi atrocities seems to have backfired for the Catholic Cardinal of Edinburg, Keith O'Brien. In a letter to Prime Minister Gordon Brown, he declared that allowing tissue from children or incapacitated adults to be used to create human-animal hybrids was a hideous mistake. "The grotesque implications of these procedures are utterly horrifying and fly in the face of all medical guidance on consent to research." He said that this behavior was last seen under the Nazis and urged the prime minister to urgently amend the legislation.

The Cardinal told BBC Scotland: "Yes, I want publicity and I use strong language so that I'll get publicity." Whether or not the Nazi card persuaded voters, it made him a target for criticism. The Anglican Archbishop of Canterbury, Dr Rowan Williams observed that: "comparisons with Nazi Germany are always a tempting conversation stopper and must be used sparingly." Lord Robert Winston, a prominent IVF doctor, termed the remarks extreme and said that they polarized opinion.

Meanwhile, the legislation creeps ahead in Parliament. A move to restrict experiments with human-animal embryos failed this week. It will be possible to keep them alive for 14 days for research purposes.