Religious heads including the Tibetan spiritual leader, the Dalai Lama,
urged British peers today to make the British government reconsider new rules allowing cloning of human embryos.
MPs approved laws late last year to allow research using stem cells to develop treatments for diseases such as leukaemia, Parkinson's and cancer.
Right-to-life groups and religious leaders oppose the move, calling it a step down a slippery slope to full human cloning despite government insistence that safeguards are in place.
The House of Lords votes on the issue today. Independent peer Lord Alton, a pro-life campaigner, has proposed a motion that would freeze the legislation until a special committee has heard exhaustive evidence from experts.
Lord Alton released a letter signed by the Dalai Lama, the Archbishop of Canterbury George Carey and Britain's Chief Rabbi Jonathan Sacks, calling on parliament to set aside the laws.
"It is precisely because we need to consider these things in detail that we shouldn't be stampeded into making decisions", Lord Alton said.
Stem cells are master cells that can develop into different cell types such as blood, brain and bones. They offer the potential to treat diseases ranging from Parkinson's, diabetes and cancers to leukaemia, hepatitis and stroke.
Government health minister Lord Hunt said Britain had solid safeguards to prevent human cloning.
Speaking on BBC radio he said: "There are no circumstances under which human cloning could take place in this country.
"But there are things we can learn which can help us research into some of our most difficult diseases".
Under the changes to the Human Fertilisation and Embryology Act of 1990 research on stem cells from human embryos will be extended but human cloning will remain illegal.
The Archbishop of Westminster Dr Cormac Murphy O'Connor, said stem cells could just as easily be obtained from adults as embryos.
But scientists say stem cells from early embryos, less than one week old, offer the greatest potential for human benefit.
Reuters