WASHINGTON, Nov. 4 - Senator Edward M. Kennedy of Massachusetts said Tuesday that negotiations on a bill to help elderly people buy prescription drugs were "on life support," in danger of dying within weeks.  Mr. Kennedy, the Democrats' senior strategist on health care issues, said the negotiations were "in free fall" because House Republicans were insisting on provisions demanded by some conservatives but detested by many Democrats.

One such provision would require standard Medicare to compete directly with private plans. Another would force Congress to vote on possible Medicare cuts if the costs of the program, including new drug benefits, grew faster than expected.

Mr. Kennedy is not a member of the conference committee trying to reconcile Medicare bills passed by the Senate and the House in June. But his comments are significant because he was a strong supporter of the bipartisan bill approved in the Senate, by a vote of 76 to 21.  Many Democrats share his views of the bill taking shape in conference. Tom Daschle of South Dakota, the Senate Democratic leader, said on Tuesday that "it's becoming less and less likely" that a Medicare bill will become law this year.

The conference chairman, Representative Bill Thomas, Republican of California, said, "We have to be more creative and figure out a way around" the developing impasse.