Some 5,000 researchers and engineers joined 48 Nobel laureates in a June letter accusing the Bush administration of ignoring "unbiased scientific advice in the policymaking that is so important to our collective welfare."

Charging that the Republican president was "compromising our future," the scientists said they support Kerry in the November 2 election because "he will restore science to its appropriate place in government."

In late September, a group called Scientists and Engineers for Change, which includes 10 Nobel laureates, hit the campaign trail in the most disputed US states to denounce Bush's policies.

"From downgrading of the position of science adviser, to tepid support for scientific funding and opportunities, to distorting scientific advice and findings, the Bush administration has pioneered a less-than ethical approach to scientific policymaking that will harm our nation for years to come," the group says on its website.

Admonishing the president's critics, Bush's science adviser John Marburger said, "I don't like to see science exploited for political purposes."

The science community has also come down hard against Bush over his decision to restrict publicly funded stem cell research.

Stem cell research supporters argue that the science could be used to find a cure to diseases such as Parkinson's and Alzheimer's.

In August 2001, Bush banned the use of public funds for stem cell research using human embryos, apart from those previously cultivated. The ban did not apply to private sector research.

"The really important questions here are ethical questions, not science questions," Marburger said.

Kerry has vowed to remove Bush's restrictions, if elected president.

To counter Bush's position, Democrats recruited the son of the late former president Ronald Reagan to speak at the Democratic National Convention in July.

Ron Reagan, whose father died after a long struggle with Alzheimer's disease, said, "We can choose between the future and the past, between reason and ignorance, between true compassion and mere ideology."

Scientists also accuse the administration of excluding views from advisory boards critical of Bush policy.

Several climate experts have complained that they were unable to include in official reports information linking pollution and global warming.

"It's so egregious what this administration is doing, particularly in regards to the environment," said Herbert Needleman, a physicist at the University of Pittsburgh, Pennsylvania. "And their whole approach to global warming has been ignorant and cynical."

Vincent Cerf, one of the Internet's architects and a Republican, accused the administration of making drastic budget cuts that could cost the United States' scientific advances, a charge the White House denies.

"Science counts, and it has not counted sufficiently in this administration," Cerf said. "The United States is at risk of losing the edge."

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