WASHINGTON - The White House raised the stakes Tuesday on the Senate's first major climate-change vote of the year, threatening to veto a Republican-led effort to stop the Environmental Protection Agency from carrying out regulations controlling greenhouse gases.

The White House, citing the environmental damage from the gulf oil spill, said the measure to overturn new EPA regulations would increase U.S. dependence on oil and other fossil fuels and "block efforts to cut pollution that threatens our health and well-being."

With the veto threat, the "resolution of disapproval" offered by Alaska Republican Lisa Murkowski has little chance of becoming law. But the outcome of Thursday's vote is seen by some as a key test as the Senate prepares to take up major climate-change legislation later this summer.

A dozen Republicans, including Murkowski, argued at a news conference Tuesday that the EPA regulations, when instituted next year, would kill jobs and usurp the authority of Congress.

Senators will make "a statement as to whether or not Congress or unelected bureaucrats at the EPA should set climate policy for this country," she said.

EPA Administrator Lisa P. Jackson, in remarks Tuesday to the Small Business Environmental Conference, dismissed warnings that the rules would hurt small businesses and said the resolution "would ignore and override scientific findings, allowing big oil companies, big refineries, and others to continue to pollute without any oversight or consequence."

The EPA actions grew out of a 2007 Supreme Court ruling that carbon dioxide and other greenhouse gases could be regulated under the Clean Air Act if it were shown that such gases endangered health.

The EPA, determining that global warming did pose a long-term danger to health, has issued standards requiring large polluters to reduce the greenhouse gases they release into the air. It exempted small sources of such gases for the next six years.

The regulations were also the basis of tough new fuel-economy standards the administration announced this year forcing a reduction in pollution from tailpipe emissions.

Murkowski's resolution has 41 cosponsors, including three moderate Democrats. A companion House resolution has 140 cosponsors.