Dr Williams attacked proposals in the Human Fertilisation and Embryology Bill which could open the door to research into hybrid embryos and which would remove the reference to the need for a father when under going fertility treatment.

He said: "The hybrid question - there has been a lot of rather extreme and alarmist talk about this and I fully accept that it is not about the breeding of monsters, but at the same time, I think there remains this very instrumentalist view of the human embryo: we use it for something and then destroy it, and I find that ethically very hard to accept.

"The hybrid embryos is just an aspect of overall attitudes to embryo research.
"In this country, more than in many others we seem to be taking for granted that it is all right to regard the human embryo as something to be used instrumentally - that is my big moral concern."

He said he "regretted" the proposals on removing the need for a father, saying it was a "downgrading of the ordinary processes of reproduction and upbringing" in favour of a "highly technological view" of what human reproduction was about.

Dr Williams also called for the Government to allow a free vote on the "big issues" of conscience, posed by the proposals on hybrid embryos in the Human Fertilisation and Embryology Bill and the removal of the clause on the need for a father.