U.S. Senate Republican leaders Thursday said they would stall confirmations of Health and Human Services officials until the Obama administration rescinds a recent order that stems from a controversy surrounding health insurance giant Humana, Inc. (HUM).

In a letter to Health and Human Services secretary Kathleen Sebelius, Senate Minority Mitch McConnell, R-Ky., and seven other Senate Republicans called for the administration to remove what it called a "gag order" on health insurance companies. The move comes after Centers for Medicare and Medicaid Services, CMS, told insurers Monday to "suspend potentially misleading mailings to beneficiaries about health care and insurance reform."

The senators warn that, until CMS reverses its actions, they "will not consent to time agreements on the confirmation of any nominees" to the Department of Health and Human Services and "associated agencies."

At issue is a probe of Humana's marketing practices by Centers for Medicare and Medicaid Services. The agency on Sept. 18 ordered Humana to cease telling its enrollees to call their lawmakers about proposed cuts to privately run Medicare plans, known as Medicare Advantage plans.

Medicare officials pointed to letters from Humana to Medicare Advantage customers suggesting that, under health-care legislation pushed by Democrats, seniors and those with disabilities "could lose many of the important benefits and services that make Medicare Advantage health plans so valuable."

Medicare officials said the letters were "misleading and confusing to beneficiaries." Humana agreed to end the mailing, but the issue brewed in Congress as Republicans suggested CMS unfairly targeted Humana.

If Senate Republicans declined to cooperate on the confirmation of HHS officials, debate on the officials would take days and consume valuable time in the Senate. Under normal circumstances, votes occur on administration officials after a short debate, or the officials are confirmed without debate or a roll-call vote.

According to a Senate Republican aide, five HHS officials have been nominated but await confirmation, while another five positions at HHS that require confirmation are vacant.

The CMS actions have occurred as the Senate Finance Committee debates health insurance legislation sponsored by its chairman, Sen. Max Baucus, D-Mont. Republicans on the panel have made a push for proposed cuts in payment rates to Medicare Advantage to be restored.

The White House has maintained Democratic health-care legislation would not result in benefit cuts to Medicare beneficiaries. At a senior citizens' center in Maryland Wednesday, Vice President Joe Biden suggested Republicans had done an about-face on Medicare after advocating for cuts to the program in the 1980s and 1990s.

"You'll continue to be able to get Medicare Advantage if that's what you choose," Biden said. "All we're doing is just cutting the padding out of the subsidies that insurance companies are already getting."

-By Patrick Yoest, Dow Jones Newswires; 202-862-3554; patrick.yoest@dowjones.com