WASHINGTON — The chairman of a Senate committee that oversees environmental issues has directed two national organizations that oppose President Bush's major clean-air initiative to turn over their financial and tax records to the Senate.

Sen. James Inhofe, R-Okla., who heads the Environment and Public Works Committee, asked for the documents 10 days after a representative of the two groups criticized Bush's Clear Skies proposal before a Senate subcommittee. Inhofe is the leading sponsor of the administration bill, which is deadlocked in his panel.

Inhofe's request was first disclosed by Cox New Service on Friday.

The executive director of the two organizations, which represent state and local air-pollution control officials, charged that the request was an attempt to intimidate critics of the measure. Democratic senators on Inhofe's committee also were dismayed by his action but declined to say so publicly because they are in the midst of sensitive negotiations with the chairman on the legislation, staffers said.

The committee's majority staff director, Andrew Wheeler, said the request for the groups' documents did not stem from their criticism of the legislation.

"It has nothing to do with Clear Skies," he said. "If we wanted to intimidate them, we would have done it before they testified, not after."

Wheeler said the panel wanted to determine whether the groups represented only regulators' views or whether they also were subsidized by outside interests, including environmentalists or foundations.

The financing, Wheeler said, "goes to who they're speaking for."

In addition to questions about possible money from outside interests, he said, there were concerns about whether the state group purports to speak for all its members when some disagree with its positions.

William Becker, executive director of both pollution-control organizations, said the groups receive no money from environmental activists or other private interests.

The administration has proposed the Clear Skies initiative as part of its effort to overhaul the way the Clean Air Act forces power plants to cut emissions.

The measure would set new emission standards for three major pollutants and introduce a market-based approach favored by industry. Proponents say it would reduce sulfur-dioxide, nitrogen-oxide and mercury emissions by 70 percent. Opponents say reductions could be achieved faster through tighter restrictions or other approaches.

Inhofe delayed a vote on the bill last week after he determined that he did not have the numbers to send it to the full Senate. The panel's 18 members are split, largely along party lines.