Senate Republicans are locked in an internal debate about whether to filibuster a debt limit increase if it is not paired with the kind of tight limits on spending they are seeking.

Minority Leader Mitch McConnell (Ky.) has been making the case to his Conference to hold off on threatening a filibuster, which would set a 60-vote threshold for passage, arguing that Republicans could later find it strategically advantageous to allow a debt ceiling increase to pass with a simple majority of Democratic votes, according to several GOP sources with direct knowledge of the discussions.

One GOP aide said Republican leaders had discussed allowing a debt limit increase to pass with just Democratic support as a way to make Democrats solely responsible for what likely will be a politically challenging vote and also to pressure Democrats to agree to “serious spending reforms.”

But several conservative GOP Senators with tea party ties on Wednesday were unwilling to rule out using the filibuster as a tool to get Democrats to agree to spending reforms such as statutory spending caps and a balanced-budget amendment that they are demanding as part of any increase in the debt ceiling.

“I am considering both options,” Sen. Jim DeMint said when asked whether he would filibuster a debt limit increase if it is not paired with the types of spending constrictions he is seeking.

The South Carolina Republican, who is viewed as a hero among tea party activists, said Senate Republicans have privately been discussing different options, including forgoing a filibuster, and described the need to raise the debt ceiling as a “failure of leadership” by President Barack Obama.

“I don’t think any Republican is going to vote to increase the debt ceiling without very serious spending caps,” DeMint said.

Another tea-party-backed Member, freshman Sen. Rand Paul (R-Ky.), said McConnell hadn’t asked him directly to hold off on threatening a filibuster on the debt limit and that it was too soon to say what his approach would be. But Paul didn’t rule out using the procedural tactic if he doesn’t get the vote on a balanced-budget amendment that he is pushing.

“I will vote to raise the debt ceiling if we pass a balanced-budget amendment,” Paul said. “We have to significantly change the way we’re doing things around here.”

McConnell’s office declined to comment, saying it would not discuss internal Conference strategy. But members of McConnell’s leadership team acknowledged that Republicans have begun to strategize privately about whether and how to employ a filibuster on the debt limit.

Republican Policy Committee Chairman John Thune said there had been “some informal conversations about this subject” but cautioned that there likely would be “a lot of evolution” in thinking as vote gets closer.

“The question is, do you want to have the Democrats deliver the votes to pass it,” the South Dakota Republican said. “If you force a 60-vote threshold, obviously it would take Republicans to get it. … What we want to do on this is … maximize the opportunity to get some of these other things passed. So I’m sure that will be part of the calculation about how to approach it.”

But Thune pointed out that McConnell and his leadership team have only so much sway in reining in their Members, noting that “any individual Senator can make that more difficult to achieve” by determining on his own to mount a filibuster.

Treasury Secretary Timothy Geithner has advised lawmakers that the government will hit the current debt ceiling on May 16 but that the Treasury Department could use “extraordinary measures” to keep the United States out of default until about July 8.

Historically, presidents have relied on lawmakers from their own parties to supply the votes to raise the debt limit, as was the case for the last increase, which passed the Senate on a 60-39 party-line vote in January 2010.

But Senate Democrats no longer have a filibuster-proof majority, so Majority Leader Harry Reid (Nev.) would have to peel off a handful of Republicans to support the increase if there is a GOP filibuster. That would make Reid’s task more difficult but also would complicate Republicans’ efforts to blame Democrats for raising the debt.

National Republican Senatorial Committee Chairman John Cornyn said forcing a Democrats-only vote in favor of the debt limit increase could help “facilitate a very important contrast” between the two parties in the next election cycle.

“I just think the next election is going to be one of contrasts,” the Texan said.

But Cornyn said the approach also could give Republicans leverage to “get something meaningful done” in the way of spending reforms.

“By doing it in a bipartisan way, that sort of eliminates the political pain or gain,” he said. “But if in fact there isn’t any prospect of getting something meaningful done, then I intend to vote against an increase in the debt limit, and one of the honors of being in the majority is that you get to supply the votes to raise it.”