WASHINGTON (AP) — Liberal Democratic members of Congress are warning President Barack Obama to not cut the Medicaid health care program as part of negotiations with Republicans over avoiding the so-called fiscal cliff.

Sen. John D. Rockefeller IV, D-W.Va., said Tuesday that Obama knows that "our votes are at stake" over the issue.

He and other Democrats held a news conference with labor and other liberal groups to say that cuts to Medicaid should not be accepted as a trade-off with Republicans in exchange for Obama's goal of raising income tax rates on the highest earners. Medicaid covers nearly 60 million low-income and disabled people.

Obama and Republicans are negotiating over ways to avoid the "fiscal cliff," steep tax increases and spending cuts that will otherwise automatically take effect in January.