Sen. John McCain (R-AZ) said Thursday it was irrational to believe Republicans have any chance of repealing the Affordable Care Act, a direct shot at conservatives in the House who have been calling on their Senate colleagues to defund the law in exchange for funding the federal government.

“I can tell you that in the U.S. Senate, will not repeal or defund Obamacare. We will not,” McCain told CNN’s Jake Tapper. “And to think we can is not rational.”

Sen. Ted Cruz (R-TX) suggested Thursday that he would stage a talking filibuster to block a Senate government spending bill that funds Obamacare. House Republicans, on the other hand, are calling on Sens. Cruz, Rand Paul (R-KY) and Mike Lee (R-UT) to follow through with their threats and defund the law, a move staunchly opposed by Senate Democrats and the White House.

“The fight here has been won. The fight over there is just beginning,” Boehner told reporters at a weekly press conference. “I expect my Senate colleagues to do everything they can to stop this law. It’s time for them to pick up the mantle and get the job done.”

Watch McCain’s comments below: