We are stepping out of the ethical mainstream and into murky waters

As someone who works in bioethics, I am sometimes ashamed to say that I am British. Most European states have signed the 1997 European Convention on Human Rights and Biomedicine. The UK has not, because it thought the ethical requirements too exacting. Similarly, in 2005, the UN General Assembly voted by more than two to one to prohibit the cloning of human embryos. The UK was again in the minority. We protested our freedom to clone.

Countries such as France, Germany, Italy and the Netherlands are technologically advanced secular states, but they set much more rigorous ethical limits on embryo experimentation. This is not, in general, because they regard the human embryo as a "human person". After all, higher primates may or may not be "persons", but they certainly command protection. Ancient woodlands are clearly not "persons", but we need very strong reasons to destroy them.

A human embryo is tiny, but it has great human significance because of what it is - the embryonic stage of a human life. It demands a significant level of protection. Nevertheless, the Secretary of State for Health recently admitted that, in the nine years for which a central record exists, the Human Fertilisation and Embryology Authority has never refused a research licence for embryo experimentation. The HFEA is like the bank that has never refused a loan. It is very hard to have confidence in a system of ethical regulation that does not reject any research proposals.

The Human Fertilisation and Embryology Bill currently before Parliament contains a number of disturbing proposals that would make the UK yet more isolated from internationally accepted ethical standards. Here I offer but a few examples.

The first and most well known of these proposals is permitting the attempt to create "human admixed" embryos by placing human DNA into cow eggs. These are the "99.9 per cent human" hybrids that have been most in the news. Those in favour of the creation of these embryos argue that it is necessary for scientific progress in stem-cell research. Nevertheless, most other countries do not think so. Few show any interest in doing this research, and Canada and Australia have both prohibited the creation of animal-human hybrid embryos. Even in this country, in private, many stem-cell scientists are quietly sceptical of the claims made for this line of research. In ten years, no team anywhere in the world has derived stem cells from a cloned human embryo. The hybrid approach is technically very difficult. In the meantime, a Japanese breakthrough has induced adult skin cells to become pluripotent without having to create embryos. This is exciting to many scientists across the world. Outside the UK, few scientists are talking about the scientific promise of hybrid embryos.

A second, to my mind even more disturbing, proposal in the Bill is to mix eggs and sperm from humans and other animals to produce "true hybrids". This is the most extreme kind of interspecies mixing and could not, even in principle, provide human stem cells. The cells would all be, say, half-human, half-cow. Thus the Bill would legalise truly crossing the species barrier, with no real public debate and for no scientific reason other than "why not?"

When cloning human embryos for research was debated in 2001, the Government emphasised that the placing of a clone in a woman would be absolutely prohibited. Yet hidden in this Bill is a third disturbing proposal - to repeal the Human Reproductive Cloning Act 2001. In certain circumstances, human reproductive cloning could actually become legal.

A final extraordinary proposal is not yet in the Bill but has been advocated by Lord Patel. He proposes waiving the need for consent when creating hybrids if the "donor" cannot be traced. Informed consent is generally regarded as a fundamental pillar of research ethics. However, if Lord Patel's amendment is adopted, scientists could use your cells to make a hybrid embryo - which is, say, 99.9 per cent you with 0.1 per cent cow - without even asking you.

The public is dimly aware of some of these proposals, but others are virtually unknown. How many people know that true hybrids are being legalised or that the Human Reproductive Cloning Act is being repealed? From an international perspective, if these proposals are approved by Parliament, many from outside will view "scientific" embryo research in the UK as we view the "scientific" whaling research conducted by Japanese scientists: as unnecessary, as unethical and as bringing science into disrepute.