Democratic Senate leaders hold a news conference on the continuing resolution with a countdown clock rolling at 4 days and change for government shutdown, Sept. 26, 2013, in Washington. (Douglas Graham/Getty Images)

Flanked by a giant clock counting down to Oct. 1, when the federal government may shut down, Senate Democratic leaders issued a stern warning today to the Republican-controlled House of Representatives: Don't play games with the spending bill.

The lawmakers said they would only accept a "clean" spending measure, known as a continuing resolution.

"We want a clean CR. We're going to have a clean CR. That's what we're going to vote for. We're not going to play any of their games," Senate Majority Leader Harry Reid said during a news conference.

"Why doesn't [House Speaker John Boehner] step up to the plate and do the right thing and allow a clean CR to go through?" said Sen. Chuck Schumer, D-N.Y.

If Senate Minority Leader Mitch McConnell and Sen. John Cornyn, R-Texas, "can stand up to the hard right with primary challenges nipping at their heels, Speaker Boehner, who's safe in his seat, ought to be able to do the same thing," Schumer added.

The Senate's current timeframe has the upper chamber voting on final passage of the continuing resolution by Saturday, just three days before the looming shutdown, but Reid wants to accelerate that vote to today and has called on Republican leadership to come to an agreement on timing.

"Every hour that ticks by puts our country closer to a shutdown. There's still time for cooler heads to prevail, but not a lot of time," Reid said.

But as the Senate tries to hasten the timeline for voting on a continuing resolution, Reid said it remained unclear whether House Republicans even have a plan.

"They don't know that they're going to do. The Tea Party's put them in this hole, and the Tea Party keeps them digging deeper and deeper," Reid said.

Reid also said that House Republicans should not include in their continuing resolution a repeal of the medical device tax - a move he called "stupid." A Reid spokesman later said Reid supports the medical device tax and thinks attaching its "repeal to the CR or the debt ceiling is 'stupid.'"

By week's end, the Senate is set to remove the language that defunds Obamacare and Democrats warned House Republicans against trying to put it back in.

"You can huff, you can puff for 21 hours, but you cannot blow the Affordable Care Act away," said Sen. Barbara Mikulski, D-Md., chairwoman of the Senate Appropriations Committee, referencing Sen. Ted Cruz's, R-Texas, 21 hour marathon speech, this week.