Sen. Jim DeMint (R-S.C.) on Friday said he would use "every tool" available to stop Senate Minority Leader Mitch McConnell's (R-Ky.) fall-back proposal for the debt-ceiling negotiations.
"I'll use every tool in Senate to stop passage of 'Plan B' blank check debt limit increase," DeMint said on Twitter.
"No Republican was elected to give President Obama more power and that's what this plan does," he added.
While DeMint didn't specify what action he would take, any single senator can filibuster a bill.
His tweets amplify previous statements the senator has made against the McConnell proposal. He said Wednesday, "Republicans weren't elected last November to make it easier to spend and borrow and add to our debt."
McConnell's plan would authorize President Obama to raise the debt ceiling but would give Congress the power to block him with a resolution of disapproval. McConnell has called it a fall-back plan so that Republicans are not forced to choose between government default or increasing the debt limit without spending cuts.
DeMint, a Tea Party favorite, carries considerable influence with conservatives in the Senate. Although McConnell's proposal has split the GOP, with significant voices raised both for and against the idea, DeMint's opposition will likely solidify the divide.
DeMint also threw his weight behind the "Cut, Cap and Balance" bill that the Republican leadership in the House rallied behind on Friday as their preferred deficit solution.
The plan would authorize a $2.4 trillion increase in the debt ceiling after Congress passes a balanced-budget amendment.
"GOP wasn't sent to Washington to cut, run & hide from debt fight with 'fallback' plan," DeMint tweeted. "We need to pass cut, cap & balance."
GOP leadership expects the House to vote on the bill next week.