The Paris attacks exposed a rift that could lead to a new government-shutdown battle

The burgeoning dispute over the issue of resettling Syrian refugees could complicate plans to keep the federal government from shutting down in December.

President Barack Obama's administration is planning to resettle approximately 10,000 refugees from the war-torn country during the 2016 fiscal year, which began on October 1. But than two-dozen state governors across the country have said over the past two days that they'll oppose letting Syrian refugees into their states.

And calls have increased to strip funding for Obama's program from a crucial spending bill that needs to pass by a December 11 deadline to keep the government funded. That could lead to a fight with the White House, which has defended its plans in recent days, and lead to a fight that could precede a shutdown.

"There are so many amendments - Planned Parenthood topped the list before the Syrian issue - that the omnibus budget bill could stall after Congress returns from its Thanksgiving break," said Greg Valliere, the chief global strategist at Horizon Investments. "Still another stopgap bill, extending until December 18, is likely ... and beyond that, no one is finalizing holiday plans."

Sen. Jeff Sessions (R-Alabama) sent a letter to the Senate Appropriations Committee on Monday that requested the cancellation of what he termed a "blank check" for refugee resettlement in the government-funding bill.

Sessions claimed that his subcommittee, the Senate Subcommittee on Immigration and the National Interest, had identified at least 26 foreign-born individuals in the US "charged with or convicted of terrorism over approximately the last year alone.:

"The barbaric attacks in Paris - an assault on civilization - add immense new urgency," he wrote in the letter.

Rep. Michael McCaul (R-Texas), the chair of the House Committee on Homeland Security, also sent a letter to Obama calling on him to immediately suspend the admission of Syrian refugees into the US.

And Sen. Ted Cruz (R-Texas), a presidential candidate, said he would introduce legislation to bar Syrian refugees from entering into the US. Cruz has been a recurring presence in these budget battles, including the famous 2013 fight over the Affordable Care Act that led to a 16-day shutdown.

"Sessions/Cruz will probably want to push for riders related to the refugee crisis. And if they do, yes I think it jeopardizes [government] funding," a Democratic Senate aide told Business Insider. "Depends whether Sessions/Cruz convince other [Republicans] to join them."

Indeed, the issue is already permeating throughout the presidential campaign trail. On Monday, former Arkansas Gov. Mike Huckabee (R) suggested that newly minted House Speaker Paul Ryan (R-Wisconsin) should "step down" if he did not "reject the importation of those fleeing the Middle East."

Retired neurosurgeon Ben Carson sent a letter to Ryan and Senate Majority Leader Mitch McConnell (R-Kentucky), urging them to move legislation that would strip funding for refugees form Syria.

Ryan said Tuesday that no Syrian refugees should be admitted unless "we can be 100% confident that they are not here to do us harm."

Republican presidential front-runner Donald Trump, who has made immigration a central theme of his campaign, has also railed for months about the Syrian refugee program, saying it's possible refugees could constitute a "Trojan horse."

Stephen Worley, a spokesman for the Senate Appropriations Committee, said refugee policies are one of a number of issues Congress would have to work through with the White House in the budget-negotiation process.

"In the coming weeks, the committee expects to be part of the effort by Congress and the White House to work through these issues to ensure that US refugee policies are in our national interest, will protect the American people, and be consistent with American values," Worley said.

The White House has defended its plans, saying the administration is thoroughly vetting potential refugees and stressing the need to do its part to help its allies in resettlement. Germany, for example, is planning to take in approximately 500,000 Syrian refugees annually over the next several years.

Obama has not weighed in on whether he would veto a potential Republican-backed budget bill hamstringing the US' ability to accept refugees. However, he gave a vehement defense of the administration's plan to take in more refugees on Monday, and forcefully rejected Republican plans to the contrary as "shameful."

"When I hear folks say that, 'Well, maybe we should just admit the Christians, but not the Muslims,'" Obama said. "When I hear political leaders suggesting that there would be a religious test for which a person who is fleeing a war torn country is admitted, when some of those folks themselves come from families who benefited from protection when they were fleeing from political persecution, that's shameful."

The president added, "That's not American."