An MP has voted in favour of a controversial procedure after being urged to do so by a grieving mum.

MP Steve Barclay voted in favour of allowing mitochondrial replacement – a procedure aimed at preventing children being born with incurable genetic diseases.

In December, Mr Barclay met with Claire Wright, of Sutton, who lost her 16-month-old son Jacob to Leigh’s Disease in 2012.

Leigh’s Disease is associated with defective mitochondrial and Mr Barclay heard first-hand the distress caused by this inherited disease.

Mrs Wright urged Mr Barclay to vote in favour of allowing the technique to be used to help mothers with this genetic fault to bear healthy children and prevent others from going through the heartbreak she endured with her son.

Mitochondrial disease is a technical glitch in the genes that act as batteries to the body’s cells.

Faulty mitochondria is genetic and is carried by around 2,500 mothers, and can cause children to be born with an array of conditions including severe epilepsy, muscular dystrophy and even acute organ failure.

Children often die in excruciating pain, which cannot be alleviated.

Mr Barclay said: “I was largely in favour of voting for before yesterday’s debate, but having heard everything that was said during the debate, and having heard Claire’s story, it confirmed my decision.

“I listened to the evidence very closely and it is fair to say the procedure has widespread support from the science community as well as leading charities.

“Yesterday’s debate gave MPs a free vote, which is the right thing to do when it comes to ethical decisions, which should not be made on party lines.”