All but four members of the Senate Republican caucus have warned that they will not vote to raise the debt ceiling in any form as Democrats are seemingly seeking a debt hike as part of their a massive $3.5 trillion spending deal.

According to The Hill, as many as 46 GOP senators signed a letter—addressed to “fellow Americans” and released on Tuesday night, Aug. 10. The letter said they would not support raising the debt ceiling regardless of whether it is brought up on its own or attached to another bill.

With a 50-50 split Senate at present, the Democrats would need at least 10 Republican votes if they want to raise the debt ceiling outside of the budget process, so the letter indicates the Republicans are ramping up pressure on Democrats to increase the nation’s borrowing limit on their own.

In the letter, the Republican group wrote: “We, the undersigned Republican Senators, are letting Senate Democrats and the American public know that we will not vote to increase the debt ceiling, whether that increase comes through a stand-alone bill, a continuing resolution, or any other vehicle.”

“This is a problem created by Democrat spending. Democrats will have to accept sole responsibility for facilitating it,” they added.

The letter was spearheaded by Sen. Ron Johnson (R-Wis.), and joined by the top rank Republicans in the Senate, such as Mitch McConnell (R-Ky.), John Thune (R-S.D.), John Barrasso (R-Wyo.) and Roy Blunt (R-Mo.).

Four Republicans refused to sign the letter included Susan Collins (R-Maine), Lisa Murkowski (R-Alaska), Richard Shelby (R-Ala.) and John Kennedy (R-La.).

Congress previously voted in 2019 to suspend the debt ceiling for two years as part of a budget deal. But the congressional suspension of the debt limit expired on Aug. 1, after the House failed to raise the ceiling. As a result, the Treasury Department said it uses “extraordinary measures” to keep the United States solvent.

The Bipartisan Policy Center estimates that Congress will need to raise the debt ceiling this fall or risk a default.

The Republicans released the letter as the Democrats appear ready to forgo trying to raise the debt ceiling on their own as part of a massive $3.5 trillion spending package they will bypass Republicans on later this year, according to The Hill.

In the budget resolution unveiled on Monday that sets up the $3.5 trillion spending plan, Senate Democrats did not mention the debt ceiling.

In a response to Democrats’ plans to pass a $3.5 trillion spending package, GOP Senate leader McConnell suggested that Republicans would not put up enough votes to raise the debt ceiling outside of the budget process.

“Here’s the comedy, they won’t let Republicans have any say in this monstrosity but they want our help raising their credit card to make it happen,” McConnell said. “Democrats want Republicans to help them raise the debt limit so they can keep spending historic sums of money with zero Republican input and zero Republican votes.”

Before the Senate voted to pass a infrastructure bill, former President Donald Trump had recommended Republicans to use debt ceiling as leverage to negotiate a better deal.