The head of Britain's largest medical research charity called on the Government yesterday to say when it will change the law on fertility treatment to allow the birth of babies with three genetic parents.
Sir Mark Walport, the director of the Wellcome Trust, was responding to a review of the technique known as "three-parent IVF" by the Nuffield Council on Bioethics, which concluded it would be an ethical option for affected families.
"In light of this report, we urge the Government to outline a timetable for considering amendments to legislation to permit use of the techniques if the Human Fertility and Embryology Authority's (HFEA) consultation in the autumn shows public support for this important technology."
The procedure, banned in the UK, is aimed at helping the 6000 British adults who are living with mitochondrial disease - defects in the small structures called mitochondria that surround the cell nucleus.
The disease is inherited but is only passed down the maternal line. One in 6500 children - about 2000 in the UK - is thought to develop a more severe form of the disease, for which there is no cure.
By removing the nucleus from an affected woman's egg, transferring it to the shell of an egg provided by a female donor who has healthy mitochondria, and then fertilising it with the sperm of the affected woman's partner, couples can avoid passing the disease on.
"It is every mother's wish to raise a healthy family, but for a small number affected by potentially devastating mitochondrial diseases this is sadly not possible. [These] techniques provide much-needed hope to these families," Sir Mark said.
Anne Milton, the Public Health Minister, announced the consultation on a change to the law by the HFEA last January. At the same time the Wellcome Trust awarded £4.4 million ($8.8 million) to Newcastle University to establish a centre for research into mitochondrial disease.
Dr Geoff Watts, chairman of the Nuffield Council inquiry whose report is published today, said: "If further research shows these techniques to be sufficiently safe and effective, we think it would be ethical for families to use them if they wished to, provided they receive an appropriate level of support. "
Critics of the technique say the therapy could mark the start of a slippery slope to large-scale manipulation of future generations. Dr Watts said use of the technique would be strictly limited to incurable mitochondrial disorders.
The inquiry panel said that as the "third parent" contributes less than one in 500 genes to the resulting child, and has no effect on its appearance or personality, there should be no need for her to be legally identifiable to the child.