Senate Appropriations Committee Chairman Richard Shelby Richard Craig ShelbyThe Hill's Morning Report - Sponsored by Facebook - Republicans lawmakers rebuke Trump on election Senate to push funding bill vote up against shutdown deadline Senate GOP eyes early exit MORE (R-Ala.) warned on Tuesday that budget negotiators need to reach an "understanding" on fiscal 2020 spending bills within days to meet a Dec. 20 funding deadline.

"I think we're going to need some kind of understanding at the end of this week or the first of next week to really get something done before the 20th," Shelby said.

Pressed on whether he was saying they needed an understanding on all 12 of the fiscal 2020 bills, Shelby responded, "We'll take what we can get."

"If we can make headway, we haven't gotten one yet," Shelby cautioned.

Shelby's comments underscore the tight time frame appropriators face as they try to avoid a shutdown days before the Christmas holiday. They'll have to decide by next week how they'll fund the government past Dec. 20 — passing either each of the 12 fiscal 2020 bills, another continuing resolution (CR) or some combination of the two.