Washington (CNN) House Speaker John Boehner faces a looming threat from conservatives to oust him as speaker, and it's tying his hands on funding the Department of Homeland Security.

Congress passed a one-week extension of funding just hours before the deadline on Friday night. It was that fear fueling Boehner's resistance to a longer-term bill, as it might prompt backlash from conservatives. President Barack Obama signed the bill, which funds the Department of Homeland Security through Friday.

Two senior House Republican sources tell CNN there's a serious concern among those close to the Speaker that if he allowed a vote on a clean DHS funding bill, conservatives would make a motion to vacate the chair, a direct challenge to his job.

Conservatives have demanded that any funding bill include a provision rolling back President Barack Obama's executive action delaying deportations for illegal immigrants. Democrats, meanwhile, remain staunchly opposed to tying the two together, and that fight has kept Congress in a stalemate over the bill all week, sending DHS right up to the funding deadline.

While the Senate passed a clean bill funding DHS through the end of the fiscal year this week, it appears conservative opposition is currently discouraging Boehner from bringing up a similar bill in the House.

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