A Senate panel fight over whether carbon dioxide should be included in a plan to limit pollutants emitted by U.S. utilities threatened on Wednesday to derail a Bush administration push for a bill this year.

A senior administration official defended the “Clear Skies” proposal at a hearing before the Senate Environment and Public Works Committee, which faces a 9-9 split when it votes on a utility air pollution bill on February 16.

Republican Sen. Lincoln Chafee of Rhode Island is expected to vote with panel Democrats against the bill because it lacks measures to cut emissions of carbon dioxide, which have been linked with global warming.

Some Republican members of the panel have threatened to abandon the proposal if the deadlock remained over the bill written by James Inhofe of Oklahoma, chairman of the committee, which closely mirrors the administration proposal.

Faced with passing a carbon-free bill or Inhofe’s, “I would recommend we do nothing,” said Democrat Joseph Lieberman of Connecticut. Lieberman made previous attempts with Republican Sen. John McCain of Arizona to pass mandatory carbon caps.

The United States is the world’s biggest emitter of heat-trapping gases such as carbon dioxide, which many scientists blame for a gradual warming of the earth’s climate. The Bush administration refused in 2001 to participate in the United Nations-backed Kyoto Treaty to rein in greenhouse gas emissions, saying it was too costly.

Inhofe’s bill is designed to reduce three major pollutants spewed by coal-burning power plants by 70 percent by 2018. It would use a cap-and-trade system allowing utilities to buy and sell permits to emit sulfur dioxide, nitrogen oxides and mercury but would not include any cuts in carbon dioxide emissions.

“Carbon mandates cannot pass the Senate,” Inhofe said at the panel hearing, pointing to numerous failed attempts in recent years to move legislation.

Democrats and Independent Sen. James Jeffords of Vermont say the bill as written gives utilities too much time and not enough protection for public health under the Clean Air Act, which has been in force since the early 1990s.

Inhofe’s bill is “the biggest rollback of the act ever presented to this committee,” Jeffords said.

With the panel deadlocked on whether to approve the bill, Inhofe could use a Senate rule to bypass the committee and call a full Senate vote as a last resort, an Inhofe aide said.

James Connaughton, chairman of the White House Council on Environmental Quality and the administration’s front-man on air issues, touted the plan as a health advancement that would prevent asthma and respiratory diseases linked to emissions.

U.S. utilities would spend $52 billion to install pollution-reduction equipment, reducing emissions at 1,300 U.S. coal plants and removing 9 million tons per year of pollutants when the plan is fully enacted, Connaughton said.

The legislation would also provide rules that are less likely to be mired in lengthy legal challenges, he said.

John Walke, an attorney with the Natural Resources Defense Council, said Inhofe’s bill “turns its back on the public and embraces polluters.” The legislation would delay some reductions until after 2025 because of “safety valve” features in the bill, Walke said.