by Tabassum Zakaria and Joanne Kenen

WASHINGTON (Reuters) Jul 19 - U.S. President George W. Bush used his first veto on Wednesday to block legislation to expand embryonic stem-cell research, putting him at odds with top scientists and most Americans, including some in his own Republican Party.
"It crosses a moral boundary that our decent society needs to respect so I vetoed it," Bush said.

The U.S. Senate approved the legislation on Tuesday. The legislation, which had also been passed by the House of Representatives, now returns to the House chamber but it does not appear to have the two-thirds majority needed to overturn the veto. It was Bush's first veto since taking office more than five years ago.

The-stem cell debate has become an issue in several Senate races in the run-up to the congressional election in November and may be a factor in the 2008 presidential contest.

But it also splits the party before the mid-term election as it is already struggling with Bush's low approval ratings and bitter divisions over other issues, such as immigration.

Democrats sharply criticized the veto and vowed to keep pressing the issue. "As long as restrictions based on a narrow ideology block progress to new cures, this issue will never be closed. Mr. President, you can veto a bill, but you can't veto hope," said Sen. Edward Kennedy, a Massachusetts Democrat.
Even conservative Republicans who generally oppose abortion are divided. Bush sees the research as destroying a human life, but others, including Senate Majority Leader Bill Frist of Tennessee and Sen. Orrin Hatch of Utah, say the embryos are slated for destruction anyway.

In 2001, Bush issued an order limiting federally funded research to 78 stem-cell lines that existed at the time, most of which proved unsuitable.

SAVING LIVES OR ENDING THEM?
Several polls have shown a clear majority of Americans support the research, which would use embryos that already exist in fertility clinics and would otherwise be thrown out. Instead the cells could be used in the search for cures of conditions like diabetes, spinal cord injuries, and Parkinson's and Alzheimer's diseases.

Anti-abortion groups have praised Bush's stance but some leading researchers and patient-advocacy groups, such as the Christopher Reeve Foundation and the Michael J. Fox Foundation for Parkinson's Research, urged Bush to reconsider.

"This bill allows important research to advance and creates an ethical framework that will ensure it is done appropriately," said Jim Greenwood, head of the Biotechnnology Industry Organization.

Britain has passed laws encouraging embryonic stem-cell research, including using cloning techniques to create tailored medical treatments. Canada and New Zealand have also passed legislation to fund embryonic stem-cell research.
Bush is the first president to complete four years in office without a veto since John Quincy Adams in the 1820s.

Reuters Health Information 2006. © 2006 Reuters Ltd.