In what it is hailed as a historic move, British MPs have voted Tuesday in favour of the creation of babies with DNA from two women and one man.
Britain is now set to become the first country to introduce laws to allow the creation of babies from three people.
In a free vote in the Commons, 382 MPs were in favour and 128 against the technique that stops genetic diseases being passed from mother to child.
During the debate, ministers said the technique was "light at the end of a dark tunnel" for families.
Proponents said the backing was "good news for progressive medicine." The Chief Medical Officer Professor Dame Sally Davies said a yes vote would put Britain at the forefront of scientific development.
A further vote is required in the House of Lords. If everything goes ahead then the first such baby could be born next year.
Critics say they will continue to fight against the technique that they said raises too many ethical and safety concerns.