Requiring the federal government to negotiate Medicare drug prices won't save money, as Democrats contend, the Congressional Budget Office said Wednesday.

"The secretary would be unable to negotiate prices across the broad range of covered Part D drugs that are more favorable than those obtained by (the plans) under current law," Donald B. Marron, the CBO's acting director, told Rep. John Dingell, D-Mich.

Dingell is author of a bill that the House will take up Friday requiring the secretary of the Health and Human Services Department to negotiate drug prices on behalf of Medicare beneficiaries. The measure is a priority of House Speaker Nancy Pelosi.

Current law prohibits the government from negotiating drug prices in Medicare Part D. Rather, insurers have that role.

House Democrats say that the government can use its leverage to strike a better deal. Dingell was not dissuaded by the letter, which quickly made its way around Capitol Hill.

"This isn't the first time the Congress and CBO differed on the amount of savings a particular bill would achieve," Dingell said. "Common sense tells you that negotiating with the purchasing power of 43 million Medicare beneficiaries behind you would result in lower drug prices."

Dingell said he was confident that Health and Human Services Secretary Mike Leavitt will be able to achieve better drug prices for seniors after the bill becomes law.