Though the procedure, commonly described as 'three person IVF', has been approved by the Human Fertilisation and Embryology Authority (HFEA), it faces objections from those who think that it violates ethical standards.
The obvious point in favour of mitochondrial transfer is that it can prevent debilitating and incurable diseases. But is the procedure safe? One of the main concerns of its critics is that tampering with DNA could have unforeseen bad effects on a child's future health and on the health of future generations.
However, parliamentarians and other critics are not merely worried about possible harms to health. Some believe that the technique is ethically problematic because of its effect on individual identity. They think that changing an egg's, or embryo's, DNA amounts to manufacturing a new being. It tampers with the very basis of what makes an individual who he or she is.
What gives an individual an identity is a contentious philosophical issue. But the small amount of DNA added by a third person's mitochondria will not affect those things that are central to identity: personality and appearance. Children born as the result of the technique are not likely to feel insecure about who they really are.
Does it matter if mitochondrial transfer destroys someone who would have been born and creates another person? Those who think that an embryo has a right to life are opponents of any procedure that involves its destruction. But changing the genetic constitution of a mother's egg (as one form of transfer requires) is no violation of anyone's rights. There is no one in the anteroom of existence whose chance to be born has been frustrated.
For some critics the ethical problem with mitochondrial transfer is not identity but human tampering with the basis of human life.
What makes human interference bad? One answer – voiced by Jacob Rees-Mogg in Parliament - is that it sends the wrong kind of message. It implies that only perfect human beings are wanted.
Genetic engineering has sinister implications for many people because of its association with eugenics policies adopted by some states in the first part of the 20th century. These had the aim of creating a more productive and healthy population by eliminating from the gene pool those regarded as unfit.
But the practice of mitochondrial transfer and the motivation behind it have nothing to do with eugenics as it was once practiced. It is not a state program designed to 'improve' the population. It allows consenting parents to have a child who will not suffer from a serious disability.
Individuals born as the result of this technique will be no less unique, no less free, and no less able to live their own lives than others. The reasons we have for respecting human individuals will apply equally to them.
The existence of the technique is no reason for disrespecting individuals who have a disability. A person should not be identified with their disability.
The purpose of mitochondrial transfer is not to produce perfect humans: it is a way of combating debilitating ailments. But the worry of many critics of genetic engineering is that this is the first step toward eugenics. There are good ethical reasons for objecting to the use of genetic engineering to make 'perfect babies'. It could lead to a division between genetic 'haves' and 'have-nots'. It could undermine parent and child relations.
But there is a crucial difference between use of genetic engineering to remove a serious disability and its use to make people more intelligent or better looking. The distinction between disability and normal variation is not always easy to make. But it is a difference worth hanging onto.
The acceptance of a technique to prevent disease does not force us to accept techniques to make 'designer babies'. But the possibility that future developments could create serious problems for society and personal life is a good reason for holding debates about proposed techniques - now and in the future.