President George W. Bush said on Wednesday (July 19) he used his first veto to block legislation expanding embryonic stem cell research, putting him at odds with top scientists, most Americans and some in his own Republican Party. "It crosses a moral boundary," Bush said. Bush acted after the U.S. Senate on Tuesday (July 18) approved the legislation, which has also been passed by the House of Representatives. But neither chamber expects to have the two-thirds majority needed to override the veto. The president signed a different bill Wednesday, the Fetus Farming Prohibition Act, which he says "prohibits one of the most egregious abuses in biomedical research, the trafficking in human foetuses that are created with the sole intent of aborting them to harvest their parts." The president said his administration has increased funding for stem cell research drawn from children, adults and the blood in umbilical cords. In 2001, Bush allowed scientists to use 78 stem-cell lines then in existence, most of which proved unsuitable for research. But he opposes expanded federally-funded research because it entails destruction of human embryos.