US: Casting his first veto since taking office more than five years ago, US president George Bush has blocked a bill that would have expanded federal funding for embryonic stem cells. Mr Bush said research on stem cells drawn from new embryos was morally wrong, regardless of its putative medical potential.
"This bill would support the taking of innocent human life in the hope of finding medical benefits for others. It crosses a moral boundary that our society needs to respect," he said.
The bill, which won comfortable majorities in both houses of Congress, has divided Republicans.
Christian conservatives back Mr Bush but more liberal Republicans, including California governor Arnold Schwarzenegger and former first lady Nancy Reagan, argue that embryonic stem-cell research is justified because it holds out the promise of treatment for conditions such as Alzheimer's and Parkinson's disease.
The vetoed bill would have limited federal funding to research on embryos produced during in-vitro fertilisation that would otherwise be discarded.
Mr Bush announced his veto in the White House, surrounded by 18 families who had children using frozen embryos left over by other couples.
"Each of these children was adopted while still an embryo and has been blessed with a chance to grow up in a loving family. These boys and girls are not spare parts," Mr Bush said.
The president has allowed federal funding only for research on stem-cell lines created before August 9th, 2001.
Scientists and the biotech industry, which lobbied hard for the bill, say they need access to more embryos if stem-cell research is to fulfil its potential for improving human health.
Despite cross-party support, the stem-cell bill is unlikely to win the two-thirds majorities in both houses that are needed to overturn a presidential veto.
Republican senator Orrin Hatch, who supported the bill, in common with Senate majority leader Bill Frist, said Mr Bush's veto was not the last word on the issue.
"It sets us back a year or so until we can finally pass a bill that will have the requisite super-majority to be able to become law. And that sets back embryonic stem-cell research another year or so," he said.
Conservative group Focus on Family Action praised Mr Bush's "character and courage" in vetoing the bill.
"Some scientists believe that one source of these cures might be embryonic stem-cell research ... Yet we must also remember that embryonic stem cells come from embryos that are destroyed for their cells. Each of these human embryos is a unique human life with inherent dignity and matchless value," he said.
White House spokesman Tony Snow rejected claims that the president was holding back science, pointing out that the veto does not affect privately funded research.
"There is a burgeoning business - as you know, a lot of people are getting rich already - in this kind of research," he said.