Republican leaders in Congress suffered more setbacks Thursday as they worked to build support for President Donald Trump's deal with Democrats to tie hurricane relief funding to a short-term debt-ceiling raise.

In addition to scattered opposition from Republican senators, the bill suffered a setback when it was rejected by the Republican Study Committee (RSC), a powerful, 155-member group of House conservatives. The growing opposition increases the chances that congressional leaders will be forced to pass the bill in the House with more votes from Democrats than from the majority party.

In a letter to House Speaker Paul Ryan, RSC chair Mark Walker (N.C.) objected to two different proposals: a standalone debt-ceiling increase and a multi-part bill like the one Trump favors. But he said a multi-part deal was even worse.

"While some have advocated for a 'clean' debt limit increase, this would simply increase the borrowing authority of the government while irresponsibly ignoring the urgency of reforms," Walker wrote. "Worse yet is attaching the debt limit to legislation that continues the status quo or even worsens the trajectory on spending, such as the deal announced yesterday by the President and Congressional Leadership. The RSC Steering Committee opposes this proposal."

The deal was struck Wednesday at the White House, during a meeting Trump held with both Democratic and Republican leadership. While his fellow Republicans looked on in disbelief, Trump agreed to a deal proposed by Senate Minority Leader Chuck Schumer (N.Y.) and House Minority Leader Nancy Pelosi (Calif.) to raise the debt limit and fund the government for three months, in addition to funding billions of dollars in hurricane relief.

Few on Capitol Hill were surprised by the RSC's opposition to the plan, including Ryan, who emphasized in a press conference Thursday morning that his party's original plans for both a debt ceiling hike and a continuing resolution to fund the government had been upended by Hurricane Harvey and the looming threat of Hurricane Irma.

"People are using their smartphones to apply for aid from FEMA even before the hurricanes land," Ryan explained, the effect of which has been to deplete emergency aid funds at an unprecedented rate. "The Treasury Secretary is worried about the nation's borrowing limit and cash flow with a new hurricane coming," he added, "and those are the concerns that trump everything else."

Ryan sidestepped a question about whether the deal, struck Wednesday between the president and the top two Democrats in Congress, had enough support to pass in the House. "We haven't done the whip count on this, so I don't know about [what] the vote count is," he said. "We thought we had more time to work on this before the hurricanes hit."

Nonetheless, there is little doubt that the Trump-Schumer deal would secure the necessary 218 votes to pass, especially with the overwhelming support the bill is expected to receive from House Democrats.