The House of Commons will vote this week on the government’s human embryology bill. It will also be voting on how far the state should regulate family life, how far MPs rather than government and arm’s-length agencies should decide on ethics and whether an MP’s “conscience” should override the liberties of ordinary citizens. The Commons will have a chance to stamp the medieval demand of the Catholic Church that MPs obey its edicts rather than their judgments.

In other words it is quite a week in parliamentary history - even without considering the merits of the legislation itself.

I was for five years a member of the relevant agency, the Human Fertilisation and Embryology Authority. Not a day passed without some mind-crunching clash of human emotions passing its desk. The authority was set up under the original 1990 act licensing in vitro fertilisation, which offered hope of pregnancy to thousands of childless couples. I doubt if any modern act has been the architect of so much happiness.

The HFEA relieved parliament of direct involvement in an ethical morass and initially steered Britain into the lead in stem-cell research.

This week parliament will vote on a bill, most of it sensible, but which attempts to return to government what was previously delegated.

The bones of contention neatly encapsulate the various regulatory tussles involved in human reproduction. They embrace abortion, regulating research into embryos, the freedom of parents to plan the children they want and the role of the state in defining parenthood.

For a libertarian it is depressing to see how little part is played by freedom in this debate. Few MPs have stopped to question whether the state should interfere either with parents or with science in these matters. In Britain statism is taken as axiomatic. Over embryology the most ferocious interventionists, such as Ann Widdecombe and Iain Duncan Smith, are on the right.

The debate is bedevilled by regular outbreaks of mad Fleet Street disease. This is based on exploiting the so-called yuk factor, a sense that “something is going on out there that we do not like and therefore must stop”. If most people knew what happened in slaughter houses they would never eat meat. If they knew how hospitals were run they would avoid them like the plague, literally. For some reason, assisting pregnancy brings out deep and dark emotions, despite its purpose in bringing joy and freedom from disease to mankind.

For no good reason the government has allowed this week’s bill to reopen a debate on abortion. The present law has 24 weeks as the appropriate limit, based arbitrarily on the moment at which an immature foetus is usually able to survive outside the womb, albeit with medical intervention. Babies born prematurely after 24 weeks are surviving with greater certainty, those born earlier are not. In other words, the limit appears about right, given its chosen assumptions.

Those who regard women as involuntary incubators of God’s souls treat all abortion as murder and therefore seek to ban it by law. I cannot see how this entitles them also to draw fine distinctions as between 24 weeks and 20, 18 or 13. Abortion should be a matter for women, couples, doctors and medical advance to resolve. Each case will be personal and unique. Parliament, having decided to interfere, should at least leave in place a limit validated by experience.

Even more yuk-strewn are chimeras, the result of using empty animal eggs as receptacles for embryo research. Nobody has the slightest interest in creating monsters (nor could they), yet this has not prevented antediluvian lobbyists and their allies in the press from shrieking “hybrid” and “Frankenstein” at every mention of chimeras.

When a man walks down the street with a pig’s ventricle in his heart, we do not look for a bolt in his neck. Research into human embryos, like treatment for kidney failure or heart disease, benefits from the use of non-human tissue. That other species may contribute to medical advance is hardly novel. I am sure research using human tissue has at times helped veterinary medicine.

Admittedly a chief reason for using animal eggs is the shortage of human ones, the result of a bad decision taken by the HFEA to ban women from selling their eggs to clinics for money, for fear they might be corrupted thereby. They fetch up to $1,000 abroad, as hundreds of female students know well.

Like the equally restrictive demand that sperm donors be identified (and not just by medical records), this has killed the market and driven patients, clinics and donors to go overseas. Why so many in the fertility business should be able to grow rich on the “charity” of unpaid donors is beyond me. Parliament should be legislating on this.

More sinister is public opposition to so-called “saviour siblings” and “designer babies”, called by the Archbishop of Canterbury “one of the most poignantly difficult areas in the whole discussion”. It is not difficult at all, yet Anglicanism feels it must embody moral equivocation.

When I first engaged in this debate some eight years ago, the screening of in vitro embryos before insertion into the womb included tests for a few avoidable conditions, such as Down’s and haemophilia. There are now tests for a wide range of illnesses, including some cancers. This allows vulnerable parents the option of not passing inherited abnormalities to their children and of saving a sick child by having another from which it could receive healthy blood.

The bill is rightly determined to help such cases as the much publicised Whitaker family, who had to go to America to have a second child pre-screened so he might be born with antibodies that could save (and have saved) his older brother from the appalling Diamond Blackfan anaemia.

The idea that liberalising the law will lead to a rash of spare-parts procreation is sheer scaremongering. Any market is open to abuse, like that in spare kidneys, but we do not ban kidney transplants as a result. Medical advance has almost eliminated from Britain the bubonic plague, leprosy, cholera and tuberculosis. Embryo and related stem-cell research may be overhyped, but they offer hope of releasing families for ever from the curse of inherited illness.

Less justified is the proposed ban on the use of sperm-sorting machines that enable couples to choose the sex of their child. With parents round the world using juju medicine of every kind to get a boy or girl, and with science now offering a safe method, only blind reaction stands in the way of this advance. It is available in America, with no shock alteration in the nation’s gender balance.

That primitive societies prefer boys is no excuse for the state interfering in this most personal aspect of family planning. It is poverty and chance that lead to girl babies being killed in some countries and being overproduced in others (by mothers continuing to have many girls until a boy arrives). Choice and the free market offer family happiness and liberation. The opposition is like that to Queen Victoria’s use of chloroform in childbirth as “defying God’s labour”.

As for the Commons debate over whether an IVF baby needs a father, words almost fail me. Of course babies are better off with fathers, but whose business is that? We do not enforce abortions on pregnant schoolgirls for lacking a husband, despite the near-certainty of such a child being born into a dysfunctional home. What are we doing about families ruined by rotten fathers? In my experience women seeking IVF, whether gay or not, are self-selected as responsible parents by virtue of being prepared to go through this uncomfortable process.

In almost all these areas, parliament in 1990 delegated decisions to an arm’s-length agency, the HFEA. It has become over-regulatory and intrusive and risks pushing Britain to the most restrictive end of the European league for assisted pregnancy, both in cost and in access to the poor.

However, anyone who thinks that parliament will do the job better should look at this week’s whipping list, with its ludicrous distinction between “government” clauses and “conscience” clauses. Every law should be on MPs’ consciences. For the most part MPs should stop meddling in how people choose to plan and protect their families. They have enough trouble with their own.

simon.jenkins@sunday-times.co.uk

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