PLANS to legalise babies being born with three genetic parents have come another step closer.

The Department of Health announcement was welcomed by Professor Doug Turnbull, who leads the Newcastle University team which invented the controversial technique to prevent serious disease from being transmitted from generation to generation.

Prof Turnbull urged the Government to draw up legislation as soon as possible because of the number of patients waiting for treatment.

Prof Turnbull said: "We are pleased that the Government is still supportive of this important technique to prevent the transmission of serious mitochondrial disease. We would welcome a firm timetable for this to be tabled for debate in Parliament and become a legal treatment.

"We have patients waiting who could greatly benefit from this new IVF technique."

A consultation was launched about the initiative, which would see the IVF technique used to prevent devastating inherited diseases, earlier this year.

In its response, the Department of Health said that the plans are to progress.

Fertility rules were changed by the Government in February, paving the way for Britain becoming the first country in the world to allow mitochondrial replacement (MR) therapy.

A Department of Health spokeswoman said that following some additional work over the summer regulations will be drawn up to be set before Parliament.

A final decision to allow the treatments will need the approval of both Houses of Parliament but could come as early as next year.

Mitochondria are tiny powerhouses in cells that generate energy and have a small amount of their own DNA, separate from the bulk of the human genetic code.

Defects in mitochondrial DNA (mtDNA) are responsible for many inherited diseases, including muscle wasting, heart problems, loss of vision, organ failure and epilepsy.

MR treatment, which employs two different IVF techniques, aims to prevent these diseases by giving babies healthy mtDNA from donor eggs.

The baby is born with normal "nuclear" DNA passed down by its parents - plus a tiny amount of mtDNA donated by a second donor "mother".

In effect the baby has three genetic parents, though the donated mtDNA contains less than one per cent of its genes.

The treatment has the potential to eradicate mitochondrial diseases from affected families.

Critics argue that allowing the treatments could be the first step towards "designer babies" and eugenics.