WASHINGTON — US House Republican leaders are setting up a showdown with Senate Democrats and the White House that puts in jeopardy billions of dollars in homeland security funds.

A much-anticipated plan emerged Friday for moving a full 2015 Department of Homeland Security funding bill and several controversial floor amendments that will targets President Barack Obama's recent immigration action.

Republicans streamed out of a caucus meeting in the Capitol basement and made clear the plan essentially will dare Senate Democrats to vote down what the lower chamber likely will send them.

And, should GOP leaders there get a handful of Democrats needed to hit the magical 60-vote threshold, House Republicans already are daring Obama to use his veto pen.

"I think it's going to be a great bill with an opportunity to say we did our work today," House Rules Committee Chairman Pete Sessions, R-Texas, told reporters. "And then we're going to hope the Senate does its work."

"We're going to start by fully funding Homeland Security," Sessions said, adding the GOP-crafted legislation also will include a provision pushed by Rep. Mick Mulvaney, R-S.C., that would prohibit a president from funding "an activity that is unconstitutional and illegal."

Republican members believe Obama's recent decision to halt deportations for millions of undocumented aliens is against the law. They are using the DHS funding bill as leverage to counter the action because the department carries out most federal immigration tasks.

"We view it as we have tried to position to American people, the House and Senate, and the president, to a position where funding Homeland Security — -- especially at a time like now — -- to make sure that we have stability … for our federal workers that are law enforcement, that are security people that are looking at the threats around the world," Sessions said,

He was referring to this week's terrorist attacks in on the Paris office of the newspaper, Charlie Hebdo, that killed 12 people and one on a store Friday that left others dead.

"What we are only trying to do is say, 'Mr. President, we will not fund the illegal activities that you have been doing," he said. "We don't have time to wait for the Supreme Court."

The House also will vote on three amendments "that will clarify how the president has been running the operations, including where the American worker is, where sex offenders are, and some ancillary language," Sessions said.

House Appropriations Committee Chairman Hal Rogers, R-Ky., told reporters GOP leaders "want to get this to the president's desk for a signature funding Homeland Security at a very tedious time in the world."

Rogers ticked off a list of agencies under DHS's purview that would need a new funding bill next month to continue operating, including the US Coast Guard.

Loren Thompson of the Lexington Institute, who also advises major defense firms, puts the amount of business those companies do with DHS in the billions.

"Coast Guard cutters and aircraft alone would probably approach $1 billion annually," Thompson said.

With the threat of a DHS-wide shutdown in mere weeks and so much business in jeopardy, Republicans are setting up a standoff with Democrats, including Obama.

And they are pointing to the Paris attacks as added leverage. House Republicans say the French situation shows the world is too dangerous to not pass their DHS bill -- with the controversial policy add-ons.

"It's a very dangerous time," Rogers said. "And I would wonder whether or not the president would have real deep misgivings not signing a bill funding the Department of Homeland Security."

Rep. Ken Cramer, R-N.D., told reporters he believes "when you look at the bill and you look at the amendments … the president, as well as a lot of Democrats, are going to have a very hard time being against it."

"When you look at what's going on in Paris as we stand here, obviously Homeland Security is a very high priority," Cramer said. "In fact, securing the homeland ought to be a much higher priority than ensuring access for undocumented workers to come across the border."

In a Wednesday blog post, House Democratic Leader Nancy Pelosi of California charged House Speaker John Boehner, R-Ohio, and his GOP colleagues with "playing politics with our national security."

The DHS funding measure and immigration amendments are expected to get a vote on the floor next week. The department's funding is set to expire on Feb. 27.

Republican leaders reject Democrats' notion that they are threatening a DHS shutdown over a policy difference with Obama.

"I don't believe that the funding of the department is in fact at risk," Boehner told reporters on Thursday..

The Mulvaney amendment would change crucial parts of the Deferred Action for Childhood Arrivals (DACA), a program supported by many Senate Democrats.

Even House Republicans wondered Friday whether GOP leaders in the Senate could get the handful of Democratic votes necessary to pass a DHS funding bill with the South Carolina member's amendment tacked on.

"It's going to go to the senate, and we'll see what the Senate does," said Rep. Tom Cole of Oklahoma, a House GOP deputy whip. "We're going to try and make this work the way the Constitution says it should work."

Notably, Cramer told reporters that there was no discussion of what to do about DHS funding should the senate send back a version of the legislation with some or all of the immigration provisions stripped out.

Nor did the caucus meeting include opposition to the plan from Republicans voiced by members who typically place national security matters over other issues, Cramer said.

Still, senior Republicans seemed cognizant of the possibility of eventually passing a "clean" Homeland Security appropriations measure, meaning one free of the immigration provisions.

"I think starting early is to try and give the Senate enough time to, No. 1, see if they can get to 60," Cole said, "and then try and give the president enough time to see what he wants to do -- if we can get the bill to him. … We can't predict what the Senate is going to do."

Email: jbennett@defensenews.com / Twitter: @bennettjohnt