If it wins final approval, as seems likely, the technique is expected to be used only sparingly, and in the cases of women who have faulty mitochondria. The resulting embryo would have nucleus DNA from the child’s parents but mitochondrial DNA from a donor.

Scientists say that the child would inherit the characteristics of the parent, other than the mitochondrial defect, rather than those of the donor.

They also say that the procedure is different from the one used to genetically modify foods, in which individual genes are usually selected to be transferred from one organism into another.

Tuesday’s vote was welcomed by Robert Meadowcroft, chief executive of the Muscular Dystrophy Campaign, who described it in a statement as a “milestone in giving women an invaluable choice, the choice to become a mother without fear of passing on a lifetime under the shadow of mitochondrial disease to their child.”

“There are currently no means to treat devastating mitochondrial diseases, which can cause muscle wastage, loss of vision, stroke-like episodes and a premature death,” the statement added. “Preventing inheritance, where possible, remains our only option, and that is why we have invested in and wholly support this pioneering technique.”

Some groups opposed to the procedure, including Human Genetics Alert, had likened it to genetic modification. “Although food crops, bacteria and animals have been genetically engineered for the last 20 years, there has been a worldwide consensus, embodied in legislation in over 60 countries, that we should not attempt to do the same with human beings,” the group said on its website.

“This is because crossing this line would lead inevitably to a future of ‘designer babies’ and a new consumer-driven eugenics,” the group said.