Washington (CNN) - Former House Speaker Newt Gingrich encouraged Congressional Republicans Wednesday to fight for the Republican Medicare proposal, despite his past criticism of the plan and the Republican loss in Tuesday's New York special election that became a referendum on the proposal.
"Saving Medicare so it is affordable with no government rationing of healthcare for seniors is the new GOP litmus test," Gingrich wrote in a letter to House and Senate Republicans. "Republicans are working to preserve a doctor-patient relationship and access to care for all seniors."
The 2012 presidential candidate said this is the third time in his career Democrats have unsuccessfully used Medicare to attack the GOP, adding that Republicans need to "stand firm against these attacks."
"The lessons of 1980 and 1995-96 are clear," Gingrich wrote, referencing the Republican electoral victories in those cycles. "The Democrats' Mediscare big lie campaign will inevitably collapse if we cheerfully insist on telling the truth."
Gingrich's apparent endorsement comes after a very public back-and-forth with House Budget Committee Chairman Rep. Paul Ryan. He originally criticized the plan publically, only to later backtrack on his comments and apologize to the Wisconsin Republican.
Under the plan originally put forward by Ryan, the government would no longer directly pay bills for senior citizens in the program. Instead, recipients would choose from a list of private insurance providers, which the federal government would subsidize.
Democrats warn the move would threaten the health care security enjoyed by older Americans and have pledged to make the GOP plan a focal point of their campaign efforts in the lead-up to the 2012 election.
Medicare was a key issue in Tuesday's special election to fill the Congressional seat in New York's 26th district, in which CNN projected a win for Democrat Kathy Hochul.
Hochul and Republican Jane Corwin attacked each other over the issue while both political parties and outside groups flooded the market with ads over the reform plan.
But the day after the election, Gingrich told GOP members to think of this time as "'Medicare 3,' a bad sequel to two bad failures."
"Paul Ryan and the House Republicans are trying to save Medicare in a period of enormous economic and fiscal difficulties," Gingrich wrote. "We need to be bold and offer real solutions that improve Medicare so we can preserve it for future generations."
- CNN's Alan Silverleib contributed to this report.