A scientist set out her argument on Wednesday for being given a British license to conduct controversial experiments which would alter the DNA of human embryos.

Critics of the proposed research said it is effectively genetically modifying human embryos and represents a "slippery slope" toward a future of designer babies.

But speaking before a meeting of Britain's Human Fertilization and Embryology Authority that will decide if she can go ahead, Kathy Niakan said the work could help improve infertility treatments and could ultimately provide "a deeper understanding of the earliest stages of human life".