Stem cell science may be advancing, but not fast or far enough to break the standoff between President Bush and Congress over federal funding for research that destroys human embryos.

Clear majorities exist in the House and Senate for a bill to loosen Bush's 2001 restrictions on public funding for embryonic stem cell research (search). Bush, opposed to the creation and destruction of human embryos for research, has promised to veto the bill if it reaches his desk.

Monday's announcement that Harvard scientists had discovered a way to fuse adult skin cells with embryonic stem cells raised the possibility that someday, all-purpose stem cells could be created without harming human embryos.

Someday. But not soon enough to change the outcome of an emotional debate looming after Congress' August recess.

"We are right where we always were," Sen. Tom Harkin, D-Iowa, a co-sponsor of the bill with Sen. Arlen Specter, R-Pa., said by telephone Monday after reading of the advance by the Harvard team.

Senate supporters of more federal funding for embryonic stem cell research claim to have at least 60 votes for overturning Bush's policy. Senate Majority Leader Bill Frist, R-Tenn., added his support last month.

Frist's office said Monday a debate and a vote on the bill will still take place in September despite the scientists' announcement and pleas by conservatives to delay the vote.

"We should not rush this debate," warned Sen. Sam Brownback, R-Kan. "If we do not rush to kill innocent human life, we will find ethical, moral ways of solving this issue."

The White House and its allies in Congress don't expect advances such as those reported by the Harvard scientists will erode support in Congress for overturning Bush's restrictions. At most, they hope the announcement might cause some undecided lawmakers -- such as Sen. George Allen, R-Va., a possible contender for the 2008 GOP presidential nomination -- to give pause before siding against the president on the issue.

"I can't imagine that it won't make a difference," White House spokesman Trent Duffy said Monday of the Harvard announcement. Stem cell studies that do not harm human embryos are "something that we all can support," he added.

Bush shows no sign of backing down on his promise to veto the bill if it reaches his desk.

"He said he would have to veto the bill," Sen. Orrin Hatch, R-Utah, said by telephone after talking with Bush Monday on Air Force One during the ride from the president's ranch in Crawford, Texas, to an event in Salt Lake City. "He feels like he would have to honor that commitment."

The Senate bill was passed by the House in May with support from 50 Republicans, not enough to override a veto.

Hatch said the scientists at Harvard and elsewhere are making interesting progress, but he doesn't believe that funding their work should come before passing the Specter-Harkin bill.

The Harvard scientists acknowledged that their work is not as far along as human embryonic stem cell research.

"I can't stress enough that this technology is not ready for prime time right now," Harvard researcher Kevin Eggan said at a briefing Monday. "It is not a replacement for those techniques that we already have for derivation of embryonic stem cells."

Frist said in July that the 22 lines of embryonic stem cells now available for research are deteriorating and don't meet the needs of scientists searching for cures. Stem cells derived from embryos can develop into any kind of tissue in the body. Scientists are looking at ways to manipulate them to replace diseased or injured tissues.