"Anything and everything," Manchin said, responding to a question on if he would object to unanimous consent requests.

Asked what that means for a government funding bill, he responded: "Everything."

"If we have to stay here until New Year's, Christmas, whatever. We've been making promises to all these thousands of people who built this country and [senators are] going to walk out of here thinking they're going to do [tax] extenders and all the things they want to do and leave miners high and dry. That's not going to happen."

Manchin's threat could be a wrinkle for leadership as they try to clear a final deck of nominations and legislation over the next week before leaving town for the Christmas holiday.

Lawmakers have until Dec. 20 to fund the government and avoid a second shutdown of the year. Negotiators are still trying to get a deal on the 12 fiscal 2020 bills. Without one, they'll need to pass another continuing resolution. Leadership has also announced deals on a mammoth National Defense Authorization Act, which sets defense policy, and Trump's trade deal with Canada and Mexico. Meanwhile, the House is heading toward a vote on impeachment articles before they leave for the break.

McConnell warned senators on Tuesday that they would need to cooperate if they were going to get everything passed in time.

"It will certainly take a great deal of cooperation and consent right here in the Senate if we intend to consider and pass these measures before the end of the year," he said.