His scheme is reminiscent of Jurassic Park but, while in the film dinosaurs were created in a laboratory, Professor Church’s ambitious plan requires a human volunteer.
He said his analysis of Neanderthal genetic code using samples from bones is complete enough to reconstruct their DNA.
He said: ‘Now I need an adventurous female human.
‘It depends on a hell of a lot of things, but I think it can be done.’
Professor Church’s plan would begin by artificially creating Neanderthal DNA based on genetic code found in fossil remains. He would put this DNA into stem cells.
These would be injected into cells from a human embryo in the early stages of life.
It is thought that the stem cells would steer the development of the hybrid embryo on Neanderthal lines, rather than human ones.
After growing in the lab for a few days, the ‘neo-Neanderthal’ embryo would be implanted in the womb of a surrogate mother – the volunteer. Professor Church, 58, is a pioneer in synthetic biology who helped initiate the Human Genome Project that mapped our DNA.
He says Neanderthals were not the lumbering brutes of the stereotype, but highly intelligent. Their brains were roughly the same size as man’s, and they made primitive tools.
He believes his project could benefit mankind.
He told German magazine Der Spiegel: ‘Neanderthals might think differently than we do. They could even be more intelligent than us.
‘When the time comes to deal with an epidemic or getting off the planet, it’s conceivable that their way of thinking could be beneficial.’
Scientists say that his plan is theoretically possible, although in Britain, like most countries, human reproductive cloning is a criminal offence.
But Professor Church’s proposal is so cutting-edge that it may not be covered by existing laws.
However, experts worry that neo-Neanderthals might lack the immunity to modern diseases to survive, and some fear that the process might lead to deformity.
There is also uncertainty over how they would fit into today’s world. Bioethicist Bernard Rollin of Colorado State University said: ‘I don’t think it’s fair to put people… into a circumstance where they are going to be mocked and possibly feared.’
In a scathing reaction, Philippa Taylor of the Christian Medical Fellowship said: ‘It is hard to know where to begin with the ethical and safety concerns.’