In an interview with the conservative Washington Examiner newspaper, Coburn criticized fellow Republicans who signed a pledge not to vote for a continuing resolution to provide routine funding for government operations unless funding for the healthcare reform law, commonly known as Obamacare, are stripped from it.
"I'd love to defund it," Coburn told the newspaper. "I'd be leading the charge if I thought this would work. But it will not work."
Coburn, a physician and a consistent opponent of the Affordable Care Act, said he opposed the Republican gambit because the votes aren't there for it to be successful.
"You're going to set an expectation among the conservatives in our party that we can achieve something that we're not able to achieve," he said. "It's not an achievable strategy. It's creating the false impression that you can do something when you can't. And it's dishonest."
Coburn said the strategy "is a good way for Republicans to lose the House."
Sen. John McCain, R-Ariz., said on Twitter Friday: "I agree with my friend Dr. Coburn: 'Tom Coburn: Campaign to defund Obamacare "dishonest," "hype."
Coburn's comments came as Sen. Richard Burr, R-N.C., said the idea of shutting down the U.S. government to block healthcare reform implementation is "the dumbest idea I've ever heard."
Support is building among congressional Republicans for using a continuing resolution as leverage to block implementation of the Affordable Care Act. Sen. Marco Rubio, R-Fla., is among the loudest voices supporting the stand, The Hill reported Friday.
Burr said Thursday stopping the funding in not achievable and argued Republicans risk taking the blame if the government is shut down over the issue.
"I think it's the dumbest idea I've ever heard," said Burr. "As long as Barack Obama is president, the Affordable Care Act is going to be law. Defunding the Affordable Care Act is not achievable through shutting down the deferral government."