The parents of a baby with a severe neurological disorder that could cut short her life have said their future happiness lies in the hands of MPs who will vote on whether or not to allow so-called 'three-parent families' today.
Vicky Holliday and Keith Newell said that allowing babies to be created with DNA from three people could prevent other children being born with genetic disorders like their one-year-old daughter Jessica, and would have a huge impact on the "future of our family".
Victoria Holliday said the vote could determine not just her family's future happiness but also other peoples.
She said: "We just want to have a choice about what we do next in terms of our family."
There is opposition to the move though as critics have argued allowing 'three-parent' families would amount to creating 'designer babies'.
Experts from academic institutions including the US Food and Drug Administration (FDA) also told that they believe "Britain will be left out on a limb, and at odds with the rest of the world, by rushing through new legislation" and said three-parent babies could be "at greater risk of cancer and premature ageing".
If today's vote in Parliament is successful it would make Britain the first country in the world to offer a procedure meaning babies could be created with DNA from three people, a technique which supporters say would be a major step in preventing genetic diseases by allowing faulty DNA to be replaced.
The would involve taking a mother's eggs and a donor egg, and replacing the nucleus of one with the other so you keep the parent's traits but without any genetic defects caused by unhealthy Mitochondria - the tiny rod-like structures in cells responsible for producing energy.