The showdown in Congress over $1.2 trillion in automatic budget cuts will be punctuated this week with a last-minute Senate deal that would replace those cuts with a new plan to evenly divide the pain between tax increases and spending cuts.

Republicans, meanwhile, are trying to play down dire warnings from the Obama administration that the automatic spending cuts, the so-called sequestration, will lead to long airport lines and increased threats of terrorism unless the two sides can strike a deficit-reduction deal by Friday.

Senate Majority Leader Harry Reid announced Monday that the chamber will vote by week's end on a bill that addresses only the $85 billion in automatic cuts set to kick in this year, as soon as April.

The Democratic plan effectively delays the automatic cuts for a second time, pushing what had been a December 2012 deadline to Jan. 2, 2014. The plan would raise $55 billion in new taxes and another $55 billion in targeted cuts divided evenly between the defense and domestic budgets.

Reid said the chamber will also vote on a Republican plan to avert the sequester, but as of Monday night, Senate Minority Leader Mitch McConnell, R-Ky., had yet to unveil the GOP's bill.

Reid's announcement comes as the two parties engaged in a game of high-stakes chicken over the sequester, with President Obama traveling the country campaign-style to boost public support while dispatching his Cabinet secretaries to warn of dire consequences if the sequester cuts take effect Friday.

At a White House press conference Monday, Homeland Security Secretary Janet Napolitano warned that the nation's borders would be less secure and airport security lines could stretch to a four-hour wait because the agency would be forced to cut its budget by 5 percent.

House Republicans, meanwhile, staged their own news conference to call on Obama to stop campaigning and instead sit down and negotiate a deal that can pass both chambers.

House Republican leaders will be under intense pressure to consider the Democratic Senate proposal, which includes raising taxes on oil companies and other corporations and on people earning more than a $1 million annually.

Republicans have so far resisted the idea of new taxes, saying Democrats won a tax increase during the "fiscal cliff" standoff late last year when they raised rates on those earning more than $400,000.

The GOP insists Obama can make budget cuts that don't adversely affect homeland security and other vital federal services, and he can do it without raising taxes.

"Mr. President, you got your tax increase," House Speaker John Boehner, R-Ohio, said Monday.

Republicans are also working to counter the White House narrative about the severity of the sequester's impact, with some GOP lawmakers accusing the White House of employing scare tactics.

Some GOP lawmakers are looking for their own alternative cuts. Among them is Sen. Tom Coburn, R-Okla., who wrote to the Office of Management and Budget and Napolitano, listing questionable projects and job openings that could be cut instead of vital services.

Among the spending Coburn highlights as "low priority" in the Homeland Security budget: zombie apocalypse training, an underwater robot, surveillance at a spring training center in Arizona, snow-cone machines and military style BearCat vehicles used to protect pumpkin festivals.