The House of Commons has voted to legalise the creation of “three parent babies” who will have genetic material from three different adults.

Proposals to allow for the procedure passed in a free vote, with 382 MPs were in favour and 128 against.

Ministers said that mitochondrial DNA transfer, where diseased parts of an embryo are removed and replaced with mitochondria from a donor adult, would represent a “light at the end of a dark tunnel” for families with hereditary mitochondrial diseases. Opponents said that the procedure raised serious ethical and safety issues.

The proposals still have to pass the House of Lords, but if that happens the first three-parent baby could be born next year.

Proponents said the backing was “good news for progressive medicine” but critics say they will continue to fight against the technique that they say raises too many ethical and safety concerns.

Estimates suggest 150 three-person babies could be born each year.

In the Commons debate, Public Health Minister Jane Ellison told the House: “This is a bold step for parliament to take, but it is a considered and informed step.

“This is world leading science within a highly respected regulatory regime.

“And for the many families affected, this is light at the end of a very dark tunnel.”

Fiona Bruce, the MP for Congleton, countered: “[This] will be passed down generations, the implications of this simply cannot be predicted.

“But one thing is for sure, once this alteration has taken place, as someone has said, once the gene is out of the bottle, once these procedures that we’re asked to authorise today go ahead, there will be no going back for society.”

Robert Flello, who represents Stoke-on-Trent South, said he feared “families will be let down tragically” due to the uncertainties in the technique and that society would be “up in arms” if this was a proposal for genetically modified crops.

But Frank Dobson, a former health secretary, argued uncertainty was “the nature of medicine and science.”

Three scientific reviews by the Human Fertilisation and Embryology Authority (HFEA) suggest the technique is “not unsafe”.

Yet some scientists argue those reviews were flawed.

Dr Ted Morrow, from the University of Sussex, believes there are still uncertainties.

“I have some concerns about the safety, I’m really not happy that the reviews have been as exemplary as other people think they are.”

Last week representives from the Church of England came out against the technique, cautioning that ethical and scientific questions remain unanswered on the issue. The Catholic Church also opposed it, pointing out that that the most common method of mitochondrial DNA transfer involved the destruction of human embryos.

Other groups, including Human Genetics Alert, say the move would open the door to further genetic modification of children in the future – so-called designer babies, genetically modified for beauty, intelligence or to be free of disease.

David King, from the campaign group, said: “Once you cross the ethical line, it is very hard not to take the next step of designer babies.”