Senate Republicans dismissed a Democratic proposal to expand Medicare on Wednesday, arguing that it would threaten competition and drive up health care costs.

Additionally, GOP leaders criticized their Democratic counterparts for continuing to debate proposals within their caucus to try to pass the $848 billion health care reform package.

“It’s like ‘Groundhog Day.’ They’re doing everything they can to get 60 votes,— Republican Policy Committee Chairman John Thune (S.D.) said, adding that the Medicare proposal is “the worst of a lot of bad ideas.—

To underscore their case, Thune, Conference Chairman Lamar Alexander (Tenn.) and Sen. John McCain (Ariz.) highlighted a letter from an official at the Mayo Clinic highly critical of the Democratic plan.

“Any plan to expand Medicare, which is the government’s largest public plan, beyond its current scope does not solve the nation’s health care crisis, but compounds it,— the letter from Jeffrey Korsmo of the Mayo Clinic said. “We believe insurance coverage can be achieved without creating or expanding a government-run, price-controlled, Medicare-like insurance model.—

The GOP trio was speaking out Wednesday in light of reports that a group of 10 liberal and moderate Democratic Senators reached tentative compromise on the health care bill that would expand Medicaid and Medicare. Under the proposal being floated by Democrats, the Office of Personnel Management would essentially run government-sponsored insurance exchanges in which private companies would be allowed to compete for uninsured and small-business customers. Democrats gathered for a special conference Wednesday evening to be briefed on the plan.