The abortion debate has been reignited in the UK by revolutionary ultrasound scans showing pictures of a 12 week-old foetus seemingly walking in the womb.
There have been calls for the legal time limit for abortions to be reduced from 24 to 12 weeks and Prime Minister Tony Blair has hinted that the law may be re-examined.
We asked six commentators for their views on abortion and the possibility of a change in the law. Please use the form at the bottom of the page to tell us what you think.
Anne Weyman is Chief Executive of the Family Planning Association (fpa)
The fpa supports the choice of women to have an abortion as early as possible and as late as necessary.
Abortion is an essential element of sexual health services, as can be seen by the fact that on average one in three women in the UK has an abortion.
Less than 2% of abortions take place at the upper end of the current time limit, but a reduction in this limit would have an extremely adverse effect on the women who opt for an abortion at a late stage.
The decision to have an abortion is one which no woman takes lightly, and this is particularly true when the decision has to be made later in pregnancy.
Such a decision may be taken for a number of reasons. Some women don't get access to the right help or advice, or have to wait for test results of fetal abnormality.
Some women simply don't recognise early signs of pregnancy, particularly teenagers, pre-menopausal women, and those who are taking regular contraception or who have irregular periods.
Some women go into denial about a pregnancy - for whatever reason - and will hope that it will 'just go away' until some months into the pregnancy.
There will also be women who present late for an abortion because they have had a significant change in their personal circumstances which makes them feel that they are unable to continue with their pregnancy, such as the breakdown of a relationship.
Improvements in access for early abortions may help to increase the proportion of abortions that are carried out early, but this will not remove the need for late abortions altogether.
For these reasons, we believe that there should be no change to the existing time limit for abortion."
Professor J J Scarisbrick is the National Chairman of LIFE
A society committed to upholding the rights of disabled born people should not be killing unborn children simply because they are disabled.
A society which is being urged to ban smacking born children and threatened with punishment for causing pain even to a slug, should repudiate all deliberate killing of human life in the womb.
At first sight, a re-examination of the time-limit for abortion is a good thing. Of course we welcome any measure that will reduce the destruction of unborn children. Women don't want abortion and all abortions, early or late, damage them psychologically and physically.
However, there is a worrying aspect to this review. The pro-abortion lobby (led by Lord Steel, the architect of the 1967 Abortion Act, and abortion providers) has seized upon this re-think on the time-limit to call for early abortion to be made even easier.
Pro-abortionists want abortion on demand up to 12 weeks - no questions asked.
They will press for early abortions, using chemicals, to be performed by nurses and in 'non-traditional' locations. They believe this will reduce the number of late abortions. It will not. It will certainly increase the amount of early abortion.
Anyway, there is no moral distinction between early human life (up to 12 weeks) and later human life (12 weeks to term). A 12-year-old is not morally more valuable than a 5-year-old. Bigger is not better. The 5-year-old is no less human than the older child, and indeed, is more deserving of our care because younger and more vulnerable.
The latest pictures of unborn children "walking" in the womb, sucking their thumbs, smiling and even crying in the womb, have pricked consciences. But human rights begin when human life begins - at fertilisation (conception). It's as human to be an embryo as it is to be a 12-week-old or a 24-week-old unborn child.
Viability is irrelevant. It is a measure of doctors' skill in sustaining premature babies - not of their moral worth.
Lord Steel of Aikwood is a former leader of the Liberal party and author of what became the 1967 Abortion Act
The abortion bill which I introduced in the House of Commons in 1966 was the seventh overdue attempt since 1953 by a private member to reform our harsh and archaic abortion laws.
The case for reform was overwhelmingly supported by the various medical organisations and most of the mainstream Protestant churches.
They were motivated as was I by revulsion at the damage caused by criminal and self-induced abortion and the hypocrisy of available subterfuge abortion on payment. Up to 50 women a year were recorded as suffering death from "septic and incomplete abortion", and the public wards of our hospitals were cluttered with similar patients.
It is necessary to remind people of that because, nearly 40 years on, the so-called "pro-life" (we are all pro-life) campaigners like to pretend that abortion in Britain was invented in 1967 with the passage of the Abortion Act.
The only difference is that the numbers are now known, whereas before they were not, and crucially the procedure is both legal and safe.
There can be no "correct" number of abortions - each one has to be judged on its own merits, "in good faith", as the act has it, by the mother and two doctors.
Back in 1966/67 the law on the upper time limit for abortion was based on the existing 28-week assumption of "viability" of a foetus contained in the Infant Life Preservation Act of 1929. As medical techniques advanced, it was agreed in 1990 to lower the upper limit to 24 weeks.
Since then, medical science has continued to advance, recording survivals at 22 weeks of pregnancy, and lurid publicity has been given to "botched" late abortions.
Opinion today remains as it was 40 years ago, namely that abortions should be carried out as early as possible.
I am increasingly drawn to the continental experience of making early abortions (up to three months) easier - and later ones more difficult, including bringing down the upper limit to 22 weeks.
Of course, any change in the law has to be carried out with care. Some severe abnormalities may not be detected until quite late in pregnancy and we should not deny mothers and their doctors the option of late abortion in such cases.
Lord Alton of Liverpool is a crossbencher in the House of Lords
I am pleased to see that the abortion issue is back on the political agenda. In recent weeks there has been a steady stream of stories demonstrating the sad reality of abortion - abortions for cleft lip and palate, teenagers obtaining abortions without their parents' knowledge and babies that have survived abortions being left to die in hospital side rooms.
But what has really reignited the abortion debate are the amazing 4D ultrasound pictures of the unborn child taken by Professor Stuart Campbell.
These beautiful images of the unborn child walking, smiling and opening and closing its eyes from as early as 12 weeks gestation illustrate even more compellingly the humanity of the unborn child.
Lord Alton: Time for a rethink
I have no doubt that these images have led many individuals to reconsider their long held views on abortion, not least Lord Steel of Aikwood, the architect of the Abortion Act 1967. Even the Prime Minister has said that new scientific evidence should be taken into account.
It is time for Parliament to reduce the upper time limit for abortions to something nearer 12 weeks-gestation.
How can anyone who has seen Professor Campbell's stunning pictures of the unborn child or witnessed unborn children from as early as 22 weeks gestation struggling for life in neonatal wards support social abortion up to 24 weeks gestation?
Abortion figures for 2003, published this week, reveal a shocking 3.2% rise overall, including an increase in abortions for girls under 16. The total figure of 181,600 is the highest ever recorded.
It was never the intention of Parliament to provide abortions on demand. As a society we must do more to reduce the number of abortions and protect unborn children and their mothers.
I have never made any secret of my total opposition to all abortion but surely even those who do not share my views entirely recognise that the Abortion Act must be revisited and the upper time limit for social abortions reduced.
Kypros Nicolaides is a Professor of Foetal Medicine at King's College Hospital, London
I would have concerns over reducing the time limit for abortions because of the potential impact on diagnosing abnormalities later on in pregnancy.
When considering the limits, we must take into account the stage of pregnancy where we can diagnose major fetal abnormalities.
Less than a third of serious problems become obvious before 11 or 12 weeks.
You wouldn't diagnose abnormalities sufficiently well before 12 weeks. And you would remove the 'luxury' of seeing how things evolve.
So if you did see something at that early stage which led you to suspect an abnormality - and there was a lower time limit on when abortions could be carried out - decisions would have to be made immediately, without knowing whether the fetus was actually affected by an abnormality.
Couples may decide they do not want to 'gamble', and may decide to have an abortion without being able to see how things develop.
If you have the time to observe how things go over the next few weeks, you see most of these babies evolve without any abnormalities.
But we must remove the hypocrisy that we don't have social abortions. If early abortions were made more acceptable, it would remove the need for late abortions.
We shouldn't change the existing 24 week limit. There will still be women who do not discover, or admit, they are pregnant until they have passed the 12th week. Think of the 14-year-old who conceals her pregnancy, and only reveals it when her pregnancy is quite advanced.
There are pregnancies which are unwanted, and women need time to decide what they want to do.
If we reduced the limit, those who need to have the option of abortion would be denied it."
Professor Stuart Campbell at London's Create Health Clinic
I began my training in gynaecology in the 1960's when at any time in the gynaecology ward there would be at least two very sick women admitted as a result of severe infection caused by a back street abortion.
I vividly recall holding the hand of a dying girl whose circulation had failed as a result of the uterine infection caused by such a procedure and my sense of rage and frustration that a young life should be lost so unnecessarily.
The 1967 Abortion Act changed everything. Deaths of women from abortion virtually disappeared overnight.
That is why I believe we need to have sensible abortion laws so that women in deprived circumstances or brutalised as a result of domestic violence should be offered termination of their unwanted pregnancy promptly, efficiently and without any shame or stigma.
For years I subscribed to the principle that up to the age of fetal viability (determined as 24 weeks gestation by the 1990 Amendment to the 1967 Act) the fetus is not a patient independent of its mother, and that if she so wished she could ask and be granted an abortion.
After fetal viability the fetus is a patient and unless extraordinary circumstances exist we should not cause the death of our fetal patient.
Recently I have begun to modify my views.
When the request for termination of pregnancy is on the basis of severe fetal abnormality, I have no strong object to the present Abortion Act. Many diagnoses of severe abnormalities cannot be made reliably until 18 or 20 weeks gestation.
However termination of pregnancy for fetal abnormality only accounts for 1% of the 175,000 terminations carried out each year in England and Wales.
It is the late termination of normal foetuses that has caused me to re-evaluate my views.
A staggering 25 000 abortions are carried out each year in England and Wales after 12 weeks gestation and even more worryingly 7,000 are performed after 17 weeks gestation. After 17 weeks the procedure is inherently more risky for the women and extremely distressing for the doctors and nurses carrying out the procedure.
These feelings were compounded when I began 3D ultrasound studies of fetuses throughout pregnancy. I was astonished to see complex co-ordinated movements from as early as 12 weeks gestation.
I have been called sentimental for indicating my distress at the thought of aborting these beautiful complex potential human beings.
Perhaps this is so, but I believe as it will be a sign of a civilised and humane society that it limits the gestational age at which normal fetuses are aborted.
My belief is that eventually we as a society will want to reduce the upper limit for abortion for social reasons to before 12 weeks gestation. However a sensible first step would be to set the limit at 18 weeks.