Britain voted on Tuesday to become the first country to allow a "three-parent" IVF technique which doctors say will prevent some inherited incurable diseases but which critics see as a step towards creating designer babies.

The treatment is called as "three-parent" in vitro fertilization (IVF) because the babies, born from genetically modified embryos, would tens to have DNA from a mother, a father and from a female donor. It is designed to help families with mitochondrial diseases, incurable conditions passed down the maternal line that affect around one in 6,500 children worldwide. After an emotionally charged 90-minute debate that some lawmakers criticized as being too short for such a serious matter, parliament voted 382 to 128 in favour of the technique, called mitochondrial donation.

The vote paves the way for a medical world first for Britain- which along with the United States has been at the forefront of scientific research on the treatments- but one that is fiercely disputed by some religious groups and other critics.

The process involves intervening in the fertilization process to remove mitochondria, which act as tiny energy-generating batteries inside cells, and which, if faulty, can cause inherited conditions such as fatal heart problems, liver failure, brain disorders, blindness and muscular dystrophy. Mitochondrial DNA is separate from DNA found in the cell nucleus and does not affect human characteristics such as hair or eye color, appearance or personality traits.