United States:President George Bush has promised to veto a new bill that would expand federal funding of stem-cell research using human embryos, declaring that it crosses a moral line he finds troubling.
The senate this week approved a measure that would allow federal funding of research using embryos from in-vitro fertilisation clinics that would otherwise be discarded, if donors approve of their use for research.
Mr Bush, who used his first veto since becoming president to block similar legislation last year, said the new bill was also unacceptable because it would allow the embryos to be destroyed.
"I believe this will encourage taxpayer money to be spent on the destruction or endangerment of living human embryos - raising serious moral concerns for millions of Americans . . . If it advances all the way through congress to my desk, I will veto it," he said.
There are no legal restrictions on private funding for embryonic stem-cell research in the US, but after he came into office, Mr Bush banned the use of federal funds for research on human embryos created after August 9th, 2001. Some researchers complain that the restriction means the number of stem-cell lines available is too small and that some have been contaminated since 2001. Advocates of embryonic stem cell research believe it could help to provide new treatments for a range of serious illnesses, including Parkinson's disease and Alzheimer's.
Many Christians, however, argue that such research is morally equivalent to abortion because extracting stem cells always involves the destruction of the embryo itself.
Mr Bush said that, instead of promoting embryonic stem-cell research, congress should give more support to research on adult stem cells, which he claimed is producing promising results.
Most researchers maintain that adult stem cells lack the flexibility of embryonic cells, which can be transformed into a great variety of specialised cells.
National Institutes of Health director Elias Zerhouni told a senate hearing last month that restrictions on federal funding of embryonic research was holding back US scientists from competing on the world stage.