US: The Senate is today expected to approve an expansion of federal funding for embryonic stem-cell research, triggering a dramatic, election-year confrontation between Congress and President George Bush, who has promised to veto the bill. Mr Bush has not vetoed any legislation since he took office, a record of restraint unmatched by US presidents since Thomas Jefferson.
The issue splits Republicans, with Christian conservatives comparing research on embryos to abortion, and moderates arguing that stem-cell research offers hope to millions suffering from illnesses that are now incurable.
Five years ago, Mr Bush issued an executive order limiting federal funding to research on stem-cell lines that existed before August 2001. Under the new legislation, which has already been approved by the House of Representatives, more cells, including those derived from embryos left over from fertility treatments, would be eligible for federally funded research.
Opening the Senate debate yesterday, majority leader Bill Frist acknowledged the issue's emotiveness within his party.
"No discussion today is as divisive as stem cells. Although not easy, we do have to confront head-on the issues around life's beginning," he said.
A prominent opponent of abortion and a committed conservative, Dr Frist created a sensation last year when he abandoned his opposition to embryonic stem-cell research. Other anti-abortion Republicans, including Utah's Orrin Hatch and Oregon's Gordon Smith, also support the legislation, which is likely to win comfortably the 60 Senate votes needed for approval.
Senate Judiciary Committee chairman Arlen Specter emphasised the bill would only use embryos derived from fertility treatments that would otherwise be discarded. He compared opposition to the bill to historical resistance to research that led to such landmark advances as vaccinations against disease and space travel. "There is just no sensible, logical reason why we would not make use of stem-cell research."
Opinion polls show that more than 70 per cent of Americans approve of embryonic stem-cell research, and Democrats are relishing Republicans' discomfort over the issue.
Missouri Republican Jim Talent faces a difficult fight in November to retain his seat and his challenger, Claire McCaskill, is highlighting the senator's opposition to the research bill.
"I must admit it is hard to understand that the president's first veto in six years would amount to saying no to doctors, researchers, patients and families. It would be saying no to lives," she said.
Mr Bush's top political adviser Karl Rove has been lobbying Republicans to oppose the bill but former first lady Nancy Reagan is leading a campaign to expand research that she believes could help people with Alzheimer's, which afflicted former president Ronald Reagan.
In an attempt to shield vulnerable Republican opponents of the new legislation, such as Pennsylvania's Rick Santorum, Republicans have introduced two other stem-cell bills. One would outlaw research on embryos from "foetal farms", where human embryos could be gestated in a non-human uterus or from human pregnancies created specifically for research and another would encourage research into adult stem-cells. Both bills are uncontroversial and are likely to be signed into law by Mr Bush.