Three-parent babies could finally be born in Britain next year after a panel set up by the fertility watchdog to assess the science said clinics should be granted permission to perform the procedure.

The fertility technique, which was developed by British scientists, allows doctors to replace an egg’s defective mitochondrial DNA with healthy DNA from a female donor to prevent children suffering debilitating conditions such as muscular dystrophy.

It is controversial because it would result in babies born with the DNA of three people - and effectively, two mothers.

A study published today, also warned that in around one in 8 cases, some defective DNA is carried over to embryos, meaning a child could still be born with disease.

Yet despite concerns, an independent panel of experts convened by the Human Fertilisation and Embryology Authority (HFEA) recommended that the procedure be approved for ‘cautious’ use in ‘specific circumstances’ such as when all other options, like screening, have proved futile.

“This is probably the most comprehensive review of the scientific research into mitochondrial donation undertaken by anyone, anywhere,” said Professor Andrew Greenfield, HFEA member and panel chair.

“We think that a cautious approach strikes the right balance between offering access to this exciting new treatment to couples at real risk of having a child with mitochondrial disease, while doing all we can to ensure that the treatment is safe and effective.”