The intense debate surrounding the use of hybrid human-animal embryos for research is set to resurface in parliament.
The Science and Technology Committee is hearing evidence from a diverse range of witnesses this afternoon as part of its inquiry into the regulation of scientific research using hybrid embryos.
The inquiry follows the publication of a government white paper proposing to ban the insertion of human dna into animal eggs to create stem cells for research purposes due to "considerable public unease".
However, advocates of the technique argue that research into motor neurone disease, Alzheimer's, and muscular atrophy could benefit if scientists are allowed to employ this method.
The committee has already heard evidence from a number of leading scientists in the field.
Neither hybrid nor chimera
Dr Lyle Armstrong of Newcastle University, who gave evidence to the committee last week, is one such scientist: he has applied for a licence to find out whether the technique could be used to grow replacement tissues for treating diabetes and spinal paralysis.
Dr Armstrong told MPs that the research was poorly understood by government officials and journalists alike.
He explained that neither "hybrid" nor "chimera" were appropriate terms for the embryos his team proposed to use, and such confusion was damaging public debate on the issue.
True chimera: the original sense of the term refers to mythical creatures such as this winged lion
"The wording is very fuzzy and unfortunate", he said.
Dr David King, the director of Human Genetics Alert, a pressure group which aims to curb unchecked development of this field, will put another side of the argument to MPs this afternoon.
Dr King feels that the research should not be allowed to go ahead as it "had very little likelihood of success".
The cells are "morally significant entities", he added, arguing that scientist are wrong to disregard public concern over the "unnaturalness" of the experiments.
This afternoon, representatives of the Scottish Council on Human Bioethics (SCHB) will also call for the prohibition of the research.
Dr Calum McKellar has said that "most people" find the proposed research "deeply offensive".
The Bishop of Swindon, a genetic scientist who was ordained in 2004, will testify alongside Dr King and the SCHB.
Later this afternoon, the committee will also hear from the Association of Medical Research Charities, Professor Raanan Gillon of Imperial College London, the Medical Research Council, the Wellcome Trust, and UK Stem Cells Foundation.
Proponents of the technique have weathered strong opposition from religious bodies and some parts of the popular press who see the research as meddling with nature and want it to be banned.
The Sun, using the word "mootant" to draw attention to the proposal that human dna could be added to eggs from cows, said it was "disgusting and unethical".
Meanwhile, the Express warned that "we could be in danger of summoning up some of the monsters of antiquity - the chimera with a mixture of lion, serpent and goat".
Responding to questions on the government's proposals, Tony Blair argued that future legislation would "allow us to have some flexibility".
He added: "We're not dead set against it, in fact the opposite."
MPs also heard evidence last week from representatives of the Human Fertilisation and Embryology Agency (HFEA).
The HFEA recently decided to postpone a decision on the legality of this research until more consultation with the public had been carried out.
They told the committee that the results of this decision would not be published until autumn 2007.
Dr Armstrong said that the delay "gives us the opportunity to explain why the science is so very important for Britain and humanity in general".
The Science and Technology Committee spoke out in support of the researchers in their 2005 report on Human Reproductive Technology and the Law, arguing that the creation of hybrids and chimeras should be made legal for research purposes provided they were then destroyed before 14 days had elapsed.
The report also put forward the idea that hybrid embryos were "less human than, and therefore pose fewer ethical problems for research than fully human embryos".
You can watch this committee live on broadband from 1615 GMT today.