Creating babies with three genetic parents via IVF in order to defeat inherited diseases has the broad support of the British public, according to a consultation into the controversial procedure.
A majority of Britons back mitochondrial replacement techniques, which are currently illegal, that could affect generations to come, fertility regulators found.
However, a large proportion of people were unsure or undecided about what they thought.
Babies born with the DNA of three parents could be made legal
Results from a major consultation exercise conducted by the Human Fertilisation and Embryology Authority (HFEA) were delivered to the Government on Wednesday, along with proposed policies and safeguards.
The public vote of support clears away a major hurdle in the path of changing the law to allow mitochondrial replacement.
But the HFEA fell short of explicitly recommending the move that would permit children to be conceived with the help of DNA donated by a second "mother".
Instead, it was left to ministers to decide whether they should ask Parliament to agree to the procedures.
Experts believe mitochondrial replacement could lead to the eradication of a host of serious inherited diseases.
Critics argue that it is the start of a slippery slope towards "designer" babies and eugenics.
Mitochondria are rod-shaped power plants in cells that supply energy. They contain their own DNA which is only passed onto offspring by mothers.
Defects in mitochondrial DNA (mDNA) give rise to a range of potentially life-threatening diseases, including a form of muscular dystrophy and conditions leading to the loss of hearing and vision, heart problems and bowel disorders.
One in 200 children are born with a mitochondrial disease each year in the UK, and an estimated 6,000 adults are believed to be affected by the conditions.
The new techniques result in the damaged mDNA being replaced by a healthy version supplied by the female donor.
In the public consultation, 56% of those questioned said they were "very" or "fairly" positive about techniques which could prevent mitochondrial disease by altering genetic make-up during IVF.
A tenth were "very" or "fairly" negative, and a third were undecided or unsure.
Patient focus group participants were "extremely positive" about the techniques, said the HFEA, though some wanted clarification of the risks.
For newcomers to the topic, the potential benefits of the techniques outweighed concerns about the potential dangers.
In its advice, the HFEA said clinics wishing to offer mitochondrial replacement should be specifically licensed. It also insisted that the Authority should approve each use of the procedures, at least initially.
Children should not have an automatic right to know the identify of mitochondrial donors, although this could occur by mutual consent, said the HFEA.
It also called for a further safety assessment once a clinic had applied to carry out one of the techniques. This followed advice from scientists that more research was needed despite there being no evidence that mitochondrial replacement is unsafe.
Professor Lisa Jardine, chair of the HFEA, said: "The Government has asked us to take the public temperature on this important and emotive issue and that is what we've done. We've found that there is broad support for permitting mitochondria replacement, to give families at risk of mitochondrial disease the chance of having a healthy child.
"Although some people have concerns about the safety of these techniques, we found that they trust the scientific experts and the regulator to know when it is appropriate to make them available to patients."
Two mitochondrial replacement procedures have been explored by scientists, pro-nuclear transfer (PNT) and maternal spindle transfer (MST). Both are variations of In-Vitro Fertilisation treatment.
PNT involves removing an early "pronucleus" containing parental DNA from a fertilised egg which has not yet had a chance to develop into a multi-cell embryo.
This is transferred to a fertilised donor egg whose own pronucleus has been removed and which contains healthy mitochondria.
The donor egg grows into an embryo and baby possessing nuclear DNA from its mother and father and mitochondrial DNA from the donor. Only nuclear DNA determines important characteristics such as gender, physical appearance and eye and hair colour.
MST has a similar outcome but occurs before fertilisation. A spindle-shaped structure containing a mother's nuclear DNA is first removed from one of her eggs. This is transplanted to a donor egg which has had its own spindle removed and is then fertilised by the intended father's sperm.
Again, the resulting embryo has DNA from two sources, one being the healthy mitochondria in the donor egg.
A new mitochondrial laboratory has now been set up in Newcastle, funded by the Wellcome Trust charity.
Mitochondrial replacement is banned because under the present law 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 exceptional circumstances.
Dr David King, director of the pressure group Human Genetics Alert, which opposes the move, said: "These techniques go far beyond anything existing in both invasiveness to the embryo and complexity so it's not surprising that they pose serious health risks to the child, risks that the HFEA refuses to properly address.
"In truth, the real forces driving this research are scientific careerism and the ideology which insists that high-tech is always best, and that no consequences can be allowed to stand in the way of the forward march of science."
A Department of Health spokesperson said: "Mitochondrial disease, such as muscular dystrophy, can have a devastating impact on the people who inherit it. People who have it live with debilitating illness, and women who are affected face passing it on to their children.
"Scientists undertaking research have developed new procedures which could stop these diseases being passed on. But such procedures would not be allowed in treatment under current law, so we asked the HFEA to consult the public as to whether we should change the law.
"Once we have received the detailed advice from the HFEA over the next few weeks, we and BIS will carefully consider it and respond in due course."
Dr Marita Pohlschmidt, director of research at the Muscular Dystrophy Campaign, said: "We respect that this is a complex issue that generates strong views both in support and opposition. The HFEA's consultation has been a crucial opportunity to share the realities of this IVF technique with the public, and to create open, transparent dialogue. We, and the families we work with, are grateful it has received the backing needed to move forward.
"The HFEA assures us that its recommendations will be made to the Secretary of State for Health by Easter. It has taken years to reach this stage - keeping up momentum now is vital. The Government must decide swiftly on whether regulations will go to vote in both Houses of Parliament."
Professor Doug Turnbull, director of the Wellcome Trust Centre for Mitochondrial Research at Newcastle University, said: "Mitochondrial DNA disease runs in families and there is no cure. The techniques we are working on here in Newcastle, could help hundreds of women have healthy children.
"We are very grateful for the detailed public engagement exercise carried out by the HFEA and welcome the supportive views of most of the public.
"We understand that more research is required but believe it is crucial that the Government moves now to draft the regulations so that mitochondrial patients in the UK will have access to this treatment."
Professor Alison Murdoch, honorary professor of reproductive medicine at Newcastle University, said: "The next step is for Government to draft the regulations needed under the Human Fertility and Embryology Act so that an application can, when appropriate, be submitted to the HFEA to permit treatment.
"We welcome the HFEA's recommendation that mitochondria donors should be thought of as tissue donors, protecting the anonymity of the donor.
"Although further discussions will be needed, we believe that the reports submitted today are a very positive step towards achieving suitable oversight for these new treatments."
The public consultation lasted six months and included a survey that involved face-to-face interviews with just under 1,000 members of the public across the UK.