UPDATE 2-Bush vetoes stem-cell bill, draws bipartisan fire

(Adds Bush quotes, reaction, background)

By Thomas Ferraro

WASHINGTON, June 20 (Reuters) - President George W. Bush on Wednesday vetoed legislation to expand federally funded embryonic stem cell research, triggering an uphill battle to override him in the Democratic-led U.S. Congress and likely pushing the issue onto the 2008 election agenda.

Two-thirds majority votes would be needed in the Senate and House of Representatives to overcome Bush's opposition and make the bill law. Backers admitted they are short of support. A few dozen of Bush's Republicans in Congress back the measure.

The president and other critics condemn the legislation as morally offensive because it would lead to the destruction of human embryos to derive stem cells.

But backers note the legislation would only permit scientists to use embryos left over from fertility treatments that would otherwise be discarded. They also say it could clear the way for possible medical advances that could help millions of people suffering with debilitating diseases.

"If this legislation became law, it would compel American taxpayers for the first time in our history to support the deliberate destruction of human embryos," Bush said. "I will not allow our nation to cross this moral line."

In addition to vetoing such legislation for the second time in two years, Bush issued an executive order to encourage scientists to work with the federal government to derive new methods to obtain stem cells without harming human embryos. He announced no new funding, however.

Critics called his order a sham and said Bush should have signed into law the stem-cell bill, which polls show is backed by more than 60 percent of American voters.