President Bush called on the Senate Wednesday to ban the cloning of human beings, a process that some say could be used in research and treatment of diseases.

"Life is creation, not a commodity," Bush said in a speech to 175 doctors, scientists, lawmakers, religious activists and disabled people.

"Advances in new biotechnology must never come at the expense of human conscience," he said. "As we seek what is possible, we must always ask what is right, and we must not forget that even the most noble ends do not justify any means."

Many in the Senate oppose using cloning to create human beings, but support using the process to create embryonic stem cells that may be used for research and the potential treatment of many diseases. 

The bill Bush favors bans all human cloning, including cloning human embryos for research.

"It would be a mistake for the U.S. Senate to allow any kind of human cloning to come out of that chamber," Bush said.

The issue is timely because of recent cloning advances, including last November's cloning of a human embryo by Massachusetts company Advanced Cell Technology. The company wants to extract stem cells from cloned embryos that could be used to grow healthy organs for patients.

Lawmakers are also considering passing either the total ban the president wants or establishing some guidelines that would essentially allow cloning for stem cell research.

Lawmakers hope to act this spring. Since neither side is pushing to allow cloning for reproductive purposes, what is essentially at the bottom of the debate is the conflict over when life begins, with the president saying the embryo from which a stem cell is harvested is a human being.

Critics of an all-out ban, like Senate Majority Leader Tom Daschle, think otherwise and say that unfair restrictions on stem cell research condemn millions of people who are suffering from debilitating diseases.

"We actually hold out the possibility of curing Parkinson's, curing diabetes, curing Alzheimer's disease, curing cancer," Daschle said Monday. "But whether or not we do depends on whether or not we will have the research and ability to provide scientists the opportunity to find those cures soon. We can do that and we can ban human cloning. The president wants to ban it all and I think he's wrong and I think the American people are on our side on this issue."

Bush aimed to counter a call from 40 Nobel prize-winning scientists, including some of the country's leading cancer and genetic researchers, for the Senate to support a measure sponsored by Sens. Ted Kennedy, D-Mass., and Dianne Feinstein, D-Calif., that would allow "therapeutic cloning." The scientists say the total ban that Republican Sen. Sam Brownback of Kansas is proposing, would have "a chilling effect an all scientific research in the U.S."

The president, of course, had his own scientists who feel differently. And perhaps to address the public relations side, he had several disabled people who say they'd like a cure for their paralysis, but only if it results from biomedical research conducted according to the highest ethical standards.

The public overwhelmingly opposes scientific experimentation on the cloning of human beings, according to a new poll that also suggests public opinion is mixed on stem cell research.

Nearly four out of five people opposed cloning, while one-third of those polled were against federal funding of stem cell research, according to the poll by the Pew Research Center for the People & the Press.

The poll of 2,002 adults was taken Feb. 25-March 10 and had an error margin of plus or minus 2.5 percentage points.

The Associated Press contributed to this report.

Wendell Goler serves as a senior White House and foreign affairs correspondent for Fox News Channel (FNC), joining the network in 1996.