At the end of a four-hour debate Feb. 24, members of the House of Lords nodded through regulations permitting two methods of mitochondrial transfer in the hope of curing illnesses such as muscular dystrophy.
They also rejected an amendment brought forward by a Catholic peer, Lord (John) Deben, to delay passing the legislation until research had been carried out to determine the safety of the proposed procedures.
The House of Commons had already approved the regulations Feb. 3, so the legislation now needs only the formality of royal assent to become law. Following the vote in the House of Commons, the Catholic bishops of England, Wales and Scotland made clear their opposition to the procedures on ethical grounds.
Scientists aiming to carry out the procedures were so confident that Parliament would back the regulations that they placed newspaper advertisements offering women 500 pounds ($772 U.S.) to donate their ova some two weeks before the vote in the House of Lords.
Lord (Frederick) Howe, an undersecretary in the Department of Health, told the House of Lords that affected families were eager to use the technologies.
"It would be cruel and perverse in my judgment to deny them that opportunity for any longer than absolutely necessary," he said.
Speaking on Vatican Radio Feb. 25, Auxiliary Bishop John Sherrington of Westminster said the passage of the regulations revealed a "very utilitarian view of the human embryo" and said that the Catholic view "is not adequately respected or understood."
He said he was "very disappointed" by the outcome of the vote in the House of Lords and was also disappointed that the arguments against the regulations were not properly aired in both houses of Parliament.
"The government will tell you that there has been a lot of scientific consultation, but I read that many international scientists are very critical of this vote and this procedure, so therefore I am surprised that there hasn't been more listening to the international voice of scientists and taking more time to move forward," Sherrington said.
"We don't know what the long-term consequences of changing the human germ line will be and we are moving into very risky territory and therefore from the perspective of public safety I worry about this move. I would have hoped that there would have been greater emphasis on caution and safety particularly as we are affecting the germ line."
Mitochondria are the biological power packs that give energy to nearly every cell of the body. If defective, cells can be starved of energy, causing muscle weakness, blindness, heart failure and death in extreme cases.
The procedures covered by the regulations include "three-parent IVF" by which material is extracted from an ovum and inserted into a donor egg before it is fertilized by the father's sperm.
The second technique, pronuclear transfer, involves up to four parents creating two embryos, which are destroyed before the maternal embryo is cloned and repackaged with parts from the donated embryo.