Senior GOP appropriators are backing away from a program to resettle Syrian refugees, jeopardizing funding to address what a leading Republican lawmaker once called “the greatest humanitarian disaster of my lifetime.”

The growing Republican opposition in the wake of Friday’s Islamic State attacks in Paris could create one of the biggest fissures in bipartisan talks over an expected fiscal 2016 omnibus spending bill, particularly if President Barack Obama remains committed to carrying out his administration’s plan to increase to 10,000 the number of Syrian refugees that are admitted in fiscal 2016.

Rep. Kay Granger, who chairs the House Appropriations subcommittee with oversight over refugee resettlement funding for the State Department, and Sen. Lindsey Graham, her Senate counterpart, are both now calling for a freeze to plans to resettle Syrian asylum seekers in the country in the wake of reports that at least one of the Paris attackers had a Syrian passport and entered Europe by blending in with the thousands of refugees who have flowed into the continent through Greece. The two State Foreign-Operations Subcommittee cardinals earlier this fall had called for higher levels of federal funding for refugee programs.

Granger said she wants to see U.S. humanitarian aid focused on refugee camps in the Middle East.

“We cannot allow Syrian refugees in the United States in the current dangerous environment,” the Texas Republican said in a Monday statement. “We have provided significant assistance to the refugees and nations in the region to address the crisis, and that should continue to be our response.”

The United States has accepted approximately 1,800 Syrians during the four-and-a-half-year civil war. The resettlement program costs $1.1 billion a year to process 70,000 refugees who arrive from around the world.

Last month, leading Republicans like Sens. John McCain of Arizona and Bob Corker of Tennessee had called for a more robust response to the refugee crisis with Corker calling it “the greatest humanitarian disaster of my lifetime.”

Graham in October introduced a bill (S 2145) to provide $1 billion in additional fiscal 2016 funding with specific permission for some of that money to be used for resettlement in the United States.

The GOP presidential hopeful, however, appeared to distance himself from that legislation on Monday when he called for a pause in the admittance of Syrians.

“The one thing I’ve learned from Paris is that we need to have a timeout on bringing refugees into this country until we have a system that we think will work,” Graham said in a Fox News Radio interview. “ So I’m calling for a timeout on Syrian refugees.”

Granger and Graham’s about face is significant given the leading role they are expected to play in shaping any final fiscal 2016 State-Foreign Operations spending legislation, which is anticipated to be folded into a broader omnibus bill. The measure (HR 2772) that Granger shepherded out of the House Appropriations Committee this summer would match the $3.06 billion in assistance that State Department refugee programs received in fiscal 2015, while its sister bill in the Senate (S 1725) would cut funding by over $415 million. There is also funding for domestic refugee resettlement in separate House and Senate bills that fund the Homeland Security and Health and Human Service departments.

“The tragic events in Paris of last week have sent shock waves through the resettlement community,” Catherine Wiesner, deputy assistant secretary of State in the Bureau of Population, Refugees and Migration, said at a Monday security forum hosted by the Center for Strategic and International Studies. “When you have governors coming out over the weekend and saying that they are not prepared to accept any more Syrian refugees in their state until they are comfortable with the security procedures, it’s sort of your worst nightmare for those who run the program.”

GOP Opposition Plan

Other well-placed Republican lawmakers signaled on Monday they intend to use their leadership positions to try to stop the resettlement.

Republican Sen. Jeff Sessions of Alabama, who chairs a Judiciary subcommittee on Immigration and the National Interest, proposed language be added to any government funding bill that provides money for the refugee resettlement program that would require Congress to hold a separate vote on the president’s resettlement plan before that funding is unlocked. The language would also order the Obama administration to propose offsets to make up for all resettlement costs.

Rep. Michael McCaul, R-Texas, chairman of the House Homeland Security Committee, called for a halt to Syrian refugee admissions until the United States has conducted a full review of security vulnerabilities his committee had identified in the resettlement process.

Tamar Hallerman contributed reporting.