Scientists have called on the British Government to give its immediate approval to laws allowing three-parent babies after experts found the techniques were safe.
The Human Fertilisation and Embryology Authority said it had examined a "voluminous" amount of data and concluded the techniques were not "unsafe" and were "potentially useful".But it said further experiments, including on human embryos, were needed.
The procedure sees donor DNA from a "second mother" implanted into a defective egg to prevent children suffering from inherited genetic conditions such as muscular dystrophy.
Supporters say the technique would allow affected couples the chance to have their own, genetically-related healthy offspring, but critics have warned it could lead to "designer children".
The Government began a consultation on draft regulations in February, asking a panel from the HFEA to examine the safety and effectiveness of two techniques.
