Democrats in the United States Congress are considering new legislation to protect the surgeon general from political interference after Richard Carmona, who held the post from 2002 until last year, claimed that the Bush administration tried to muzzle him.
Dr Carmona told a congressional committee last week he was prevented from giving the public accurate scientific information on issues such as stem-cell research and preventing teen pregnancies.
"Anything that doesn't fit into the political appointees' ideological, theological or political agenda is often ignored, marginalised or simply buried.
"The problem with this approach is that in public health, as in a democracy, there is nothing worse than ignoring science or marginalising the voice of science for reasons driven by changing political winds," he said.
A former army doctor and deputy sheriff, Dr Carmona said he was told to mention President George Bush three times on every page of his speeches but was ordered not to speak about the national debate over whether the federal government should fund embryonic stem-cell research.
Federal funding for embryonic stem-cell research is allowed only for research using embryonic stem-cell lines created on or before August 9th, 2001, and Mr Bush last month vetoed a bill that would have allowed federal funding for research using stem cells derived from human embryos originally created for fertility treatments and willingly donated by patients.
"Much of the discussion was being driven by theology, ideology (and) preconceived beliefs that were scientifically incorrect. I thought, 'This is a perfect example of the surgeon general being able to step forward, educate the American public.' [ but]. . . I was blocked at every turn. I was told the decision had already been made - 'Stand down. Don't talk about it.' That information was removed from my speeches," Dr Carmona told the committee.
The former surgeon general said he was also discouraged from speaking about the Special Olympics because of the Kennedy family's association with the games.
Henry Waxman, chairman of the Government Oversight Committee in the House of Representatives, said that Congress should take steps to insulate the surgeon general's office from political interference. "It is the doctor to the nation. That person needs to have credibility, independence and to speak about science. The public expects that a surgeon general will be immune from political pressure and be allowed to express his or her professional views based on the best available science," Mr Waxman said.
Dr Carmona's testimony came as Mr Bush's latest nominee for the post of surgeon general, James Holsinger, faced tough questions from senators over his attitude to homosexuality and his stance on stem-cell research.
Dr Holsinger, whose appointment must be confirmed by the Senate, wrote a paper for the United Methodist Church in 1991 in which he argued that homosexuality is not natural or healthy.
Last week, Dr Holsinger sought to distance himself from the paper: "It doesn't represent who I am today, and it represented a specific time, a specific context, and a specific purpose."
When Senator Edward Kennedy suggested that almost all US scientists, including the director of the National Institutes for Health, believe that the restriction on funding for stem-cell research is misguided, Dr Holsinger sidestepped the issue.
"I am not as informed on both the science on current stem-cell work as well as some of the new alternative processes that are coming. I simply do not feel comfortable giving you my opinion when I don't feel I've had the proper time to study it," he said.