Members of the public are being asked for their verdict on allowing the creation of IVF babies with three genetic parents.
What they say could pave the way to a landmark change in the law as early as next year that would affect future generations.
The controversy surrounds "uncharted territory" techniques aimed at preventing a special category of diseases caused by inherited genes.
They involve children being conceived with the help of a third genetic "parent" - a woman whose donated egg provides a source of replacement healthy DNA. A baby created this way would have a full compliment of nuclear DNA from its mother and father, plus a tiny amount of donated mitochondrial DNA.
Mitochondria are rod-like bodies in the cell which act as powerhouses, supplying energy. They have their own set of genes, separate from those in the cell nucleus, which are only passed on by mothers.
Defects in mitochondrial DNA give rise to a range of serious and potentially life-threatening diseases including a form of muscular dystrophy and conditions leading to the loss of hearing and vision, heart problems and intestinal disorders.
The new mitochondrial replacement treatments would remove the damaged DNA, thereby breaking the generational chain of disease. But they are banned because any tampering with inherited genetic material in clinics is illegal.
A window has deliberately been left in the Human Fertilisation and Embryology Act, allowing this blanket rule to be changed by Parliament in certain circumstances. But first ministers must be satisfied that the techniques are ethically acceptable to the public.
Regulators have now launched a large-scale public consultation exercise aimed at canvassing the opinions of ordinary people rather than experts. It runs until December 7, with a report being submitted to the Government next spring.
A change in the law voted in by Parliament could quickly follow. But it is unlikely that this would see the immediate introduction of mitochondrial replacement. The final say on whether treatments can go ahead will lie with the Human Fertilisation and Embryology Authority (HFEA) which regulates IVF clinics and fertility research.