Scientists should be allowed to create human-animal hybrid embryos in the search for treatments for nervous system disorders, a Government advisory body said yesterday.

The Human Genetics Commission will give its unanimous backing to the research in a public consultation to be carried out later this year by the Human Fertilisation and Embryology Authority.

British scientists have applied for licences to create hybrid embryos that would be around 99.9 per cent human and 0.1 per cent animal to produce embryonic stem cells - the body's building blocks that can grow into all other types of cells.

They want to use stem cells to understand and develop therapies for diseases such as Alzheimer's, Parkinson's, cystic fibrosis, motor neurone disease and Huntington's. The hybrid embryos would be destroyed within 14 days when no bigger than a pinhead.

Sir John Sulston, the HGC deputy chairman, said: "It seems to me extremely clear that we already have a very satisfactory agreement with the rule which allows experiments up to 14 days. The research which is now being proposed is no different."