(CNN) - Conservative Republican senators, led by Jim DeMint of South Carolina, are warning all other senators they will block any attempts to slip controversial legislation through the Senate in the final hours before the upcoming recess, unless they sign off on it first.
"What happens is at the end of a session, crap gets out of here that nobody knows what's in it and we're not going to do it anymore," Oklahoma Sen. Tom Coburn told CNN.
At issue are last minute requests from senators from both parties to get legislation cleared by unanimous consent, an often-used time saving parliamentary procedure that allows measures to pass without a recorded vote. As a recess approaches, it's common for dozens of measures to pass by UC, as the procedure is known on Capitol Hill.
"We said if you're going to try to give bills UC, give us 72 hours and give us a [Congressional Budget Office] score. Nobody said no, we just said give us time," Coburn said.
The warning came in a letter to Senate offices on behalf of the Senate Steering Committee, a conservative group of senators chaired by DeMint. It said any bill submitted after Tuesday would be blocked because there would not be enough time to vet the legislation ahead of the recess, which could start as early as Thursday.
'We've done this before," DeMint said. "All we're asking is that if folks want unanimous consent or something before we leave, to give us a few days to ready it and try to clear it."
DeMint, who told CNN that 40 to 50 pieces of legislation have already been submitted to his group for review, said he's tired of "trying to read things in the cloakroom while people are heading for the airport."
A top Democratic leadership aide insisted the conservative senators' complaints are overblown because most of the items that pass by UC are no more controversial than a recent measure designating September 16, 2010 as "American Legion Day."
However, DeMint spokesman Wesley Denton said that's because DeMint and others had blocked the more controversial bills.