Republican lawmakers said they would support a contempt citation against President Bush's health secretary if he didn't provide information in an investigation into the U.S. Food and Drug Administration.

Health and Human Services Secretary Mike Leavitt, testifying at a House panel Thursday, said he would work to resolve the demand by the letter's stated deadline of today. The letter, requesting documents and interviews with certain FDA employees, was signed by top Democrats on the House Energy and Commerce Committee as well as Republican Reps. Joe Barton of Texas and John Shimkus of Illinois.

The committee's oversight subcommittee is investigating whether FDA Commissioner Andrew von Eschenbach gave misleading testimony on Sanofi-Aventis SA's antibiotic Ketek during a committee hearing in March. Ketek has been linked to fatal side effects. In a Feb. 11 letter to the House panel, Leavitt, a former Utah governor, didn't comply with a subpoena requesting briefing papers used to prepare von Eschenbach for his testimony.

"We're going to respond and have discussions over the next few days," Leavitt said in an interview during a break in the hearing Thursday. "I feel optimistic."

Lawmakers of both parties warned in their letter, dated Wednesday, that they would back a contempt citation against Leavitt unless he produced the briefing papers or allowed the lawmakers to see the documents and interview FDA staff.

Leavitt, in his Feb. 11 letter, cited a possible "chilling effect" as reason for withholding the documents, according to the committee's letter, distributed to the press at the hearing. This isn't a legitimate reason for ignoring the subpoena, the committee said in its written response.

"Moreover, you have not asserted executive privilege and the records are not classified," the lawmakers said in the letter. "Under these circumstances, and given a long line of precedents established by this committee, Congress, and the courts, the records must be produced."

Leavitt shouldn't try to block the committee from proceeding with its investigation, Barton said during the hearing.

"I don't want to have to stand up on the floor and support a contempt citation, but if I have to I will," he said. "We have made a good sense effort to accommodate the needs of the administration."