Britain could become the first country in the world to allow the creation of babies with DNA from three parents on Tuesday in a move that has divided Britons and pitted campaigners against religious leaders.

Lawmakers in Parliament are set to vote on mitochondrial DNA, or mDNA, donation techniques for in vitro fertilization, or IVF, aimed at preventing serious inherited diseases being passed on from mother to son.

Under the proposed change to the laws on IVF, as well as receiving the usual "nuclear" DNA from its mother and father, the embryo would also include a small amount of healthy mDNA from a woman donor.

"Today marks a historic day for the future of modern medicine as Parliament debates whether the UK should become the first country to allow mitochondrial donation to be used in IVF treatment," Sally Davies, Chief Medical Officer for England, wrote in The Daily Telegraph newspaper.

The change could apply to up to 2,500 women of reproductive age in Britain with hereditary mitochondrial diseases, but opponents say it opens the way to the possibility of "designer babies".

Mitochondrial DNA is passed through the mother, and mitochondrial diseases cause symptoms ranging from poor vision to diabetes and muscle wasting.

British health officials estimate around 125 babies are born with the mutations in Britain every year.

Members of Parliament are due to hold a 90-minute debate and then have a free vote on the issue, meaning they can vote according to their conscience rather than party lines.

The vote is expected to pass and the motion would then move to the House of Lords, the upper chamber of Parliament, for final approval later this month.

The law would allow Britain's Human Fertilization and Embryology Authority to authorize the procedure, and a pioneering research center in Newcastle on Tyne is expected to be the first where it would take place.

The first babies with three parents could be born next year if MPs vote in favor of the change.

International charities wrote an open letter to MPs ahead of the historic vote urging them to back the change, saying it "offers families the first glimmer of hope that they might be able to have a baby that will live without pain and suffering".