In January 2004 the Government announced that the Human Fertilisation and Embryology Act 1990 was to be reviewed, and appointed a House of Commons Science and Technology Committee to consider the matter.

After heated debate, the committee issued a report in March 2005, Human Reproductive Technologies and the Law, opposing a ban on hybrid embryos.

Dissenting members immediately issued their own report, claiming that the official report “is unbalanced, light on ethics, goes too far in the direction of deregulation, and is too dismissive of public opinion and much of the evidence”.

Also in 2005 the Department of Health launched a consultation on the creation of human hybrids. It received some 340 responses from scientists, patient groups, religious bodies and members of the public. Most responses from the public favoured a ban.

In late 2005, as part of a consultation on the whole issue, Suzi Leather, then chairman of the Human Fertilisation and Embryology Authority (HFEA), said: “The pace of development means that we need Parliament to provide an updated framework for regulation to meet the challenges of the years to come.”

As a result of the consultation, the Government, in December 2006, proposed a ban on the creation of interspecies embryos.

In March last year, however, the House of Commons Science and Technology Committee issued a second report, again opposing a ban, this time without dissent. It stated: “We find that the creation of human-animal chimera or hybrid embryos, and specifically cytoplasmic hybrid embryos, is necessary for research.”

A letter signed by 223 medical charities and patient organisations was sent to the Government, also opposing the ban. This was backed by the HFEA’s own consultation report.

In May last year, the Bill was changed to drop the ban.