Senate Democrats will search this week for a final few votes they would need to thwart a filibuster on legislation that would allow the government to negotiate Medicare prescription drug prices.

Debate begins Monday on a motion to proceed to the bill (S 3). Bill supporters are at least two votes short of the 60 required to invoke cloture, or limit debate, and break a filibuster.

Democrats are in a similar situation with legislation (S 5) passed last week that would expand federal funding of embryonic stem cell research: on the brink of securing enough votes for victory but coming up short. In the case of the stem cell bill, supporters need one more vote to override an expected veto.

The prescription drug legislation would not require the secretary of Health and Human Services to negotiate drug prices, but it would lift restrictions on negotiations that have been in place since the drug benefit law (PL 108-173) was enacted in 2003. It also would require the disclosure of cost and price data that have not been made available to Congress.

Data disclosure would allow support agencies such as the Congressional Budget Office to measure the effectiveness of the program and determine how changes might affect its overall cost.

Most Republicans, the White House and the drug industry oppose the bill.

Max Baucus, D-Mont., will manage the bill’s debate on the Senate floor.

If the motion to call up the bill is successful, Majority Leader Harry Reid, D-Nev., will file a cloture motion Monday to proceed to a vote on the bill, according to a spokesman for Reid. That cloture vote would come Wednesday.

In 2006, Maine Republican Olympia J. Snowe offered an amendment to a Senate budget resolution in favor of government negotiation. One past supporter of Snowe’s amendment, South Carolina Republican Lindsey Graham, may be wavering on the current bill. A spokesman for Graham said last week the senator had not decided how he will vote. If Graham does not support it, that would likely leave Democrats with 58 votes.

Charles E. Grassley, R-Iowa, has been the bill’s most vocal opponent. Asked on April 12 whether he thought Democrats could find 60 votes, he said, “I hope not.”

Baucus’ bill is not nearly as far reaching as a House bill (HR 4), passed in January, that would require government negotiations.

Snowe and others have criticized the Senate legislation, deeming it too weak. But Baucus’ main priority is getting the Senate bill passed and into conference.

President Bush has issued a veto threat on the House legislation. Last week, Health and Human Services Secretary Michael O. Leavitt disparaged the concept of government negotiations as an infringement on what the administration sees as an efficient private market.

The Pharmaceutical Research and Manufacturers of America (PhRMA), the drug industry’s lobbying group, has for months sponsored an advertising campaign urging lawmakers to leave the drug benefit program alone.

Baucus said he has discussed the Senate bill with the drug industry and that PhRMA did not look favorably on it, despite its less stringent language compared with the House measure. “Just degrees of discontent,” he said.