Updated: 9:36 p.m.

Sen. Jim DeMint warned his colleagues Monday night that he would place a hold on all legislation that has not been “hot-lined” by the chamber or has not been cleared by his office before the close of business Tuesday.

Although the South Carolina Republican has objected for years to the hot-lining of legislation until his staff at the Republican Steering Committee has reviewed it, DeMint’s threat to essentially shut down legislation in the chamber is remarkable.

Traditionally, the Senate passes noncontroversial measures by unanimous consent at the end of most workdays, a process known as hot-lining. DeMint, Sen. Tom Coburn (R-Okla.) and others have fought against the practice for years and have dedicated staff members to reviewing bills that are to be hot-lined.

As a result, Senate Majority Leader Harry Reid (D-Nev.) and Minority Leader Mitch McConnell (R-Ky.) have generally given DeMint, Coburn and others time to review legislation before proceeding with unanimous consent agreements.

But in a terse e-mail sent to all 100 Senate chiefs of staff Monday evening, Steering Committee Chief of Staff Bret Bernhardt warned that DeMint would place a hold on any legislation that had not been hot-lined or been cleared by his office before the close of business Tuesday.

“The Executive Committee of the Senate Steering Committee has asked the Steering Committee staff to hold all bills that have not been hotlined by close of business Tuesday,” Bernhardt wrote. “If there are any bills you would like cleared before we go out, please get them to the Steering Committee staff along with a CBO score, if applicable, by close-of-business on Tuesday.”

Democratic and Republican aides alike were stunned, arguing that DeMint had essentially made a unilateral decision to end legislative activity in the Senate.

Rodell Mollineau, a spokesman for Reid, derided the missive and questioned McConnell’s control of the Senate Republican Conference.

“I wonder what Minority Leader McConnell thinks about Minority Leader DeMint’s unilateral declaration,” he said. “One thing I know for sure is if their Conference continues to follow the lead of the junior Senator from South Carolina, then the only title that proceeds his name or Sen. McConnell’s name will be Minority Leader.”

The practical effect of DeMint’s warning is unclear; most of the Senate’s remaining major legislation will likely be handled after lawmakers vote Tuesday on a cloture motion to begin debate on a continuing resolution to keep the government funded when the new fiscal year begins Oct. 1. The Senate is expected to adjourn this week for the midterm Congressional campaigns.

However, the political ramifications, particularly within the GOP Conference, could be significant. DeMint has spent much of his career operating as an outsider and has repeatedly ruffled the feathers of his Republican colleagues. His crusade against earmarks and demands for ideological purity have been particularly troublesome to the conference’s “Old Bulls” and appropriators.

DeMint spokesman Wesley Denton defended the Republican’s decision, arguing that the move is necessary to keep the Senate from passing a slew of expensive measures in the last minutes of the session.

“Americans are sick of Washington ramming through bills that no one reads. Big spenders play a hide-the-bill game at the end of every Congress, hoping to pass secret bills with deficit spending and new regulations without any debate or even a vote,” Denton said.

“The Senate Steering Committee has simply asked that if a Senator wants to pass a bill before recess, allow 48 hours for Senators to review the bill and for the CBO to score it,” he added. “If you wait until Thursday night and then unveil some big spending bill, your bill is not going to pass.”