By David Lawder and Susan Cornwell
WASHINGTON (Reuters) - U.S. Senate Democrats were poised on Tuesday to torpedo Republicans' plans to block President Obama's immigration action through a Department of Homeland Security funding bill, setting up a month-end showdown that could put the agency at risk.
Congress faces a Feb. 27 deadline to renew funding for the department, which spearheads domestic counterterrorism efforts and secures U.S. borders, airports and coastal waters. A DHS spending bill passed by House Republicans last month, however, would ban spending on Obama's recent executive orders lifting the threat of deportation for millions of undocumented immigrants.
Senate Democrats said they would block the House bill in a procedural vote on Tuesday afternoon, forcing Republicans to come up with an alternative funding plan. Republicans need 60 votes for the measure to proceed to final passage; they only have a 54-vote majority.
Senator Claire McCaskill, a Missouri Democrat who has criticized Obama's executive action last fall, told reporters she would vote to block the Republican plan.
"To put uncertainty in America around homeland security, this seems to be very bad timing," she said, noting recent attacks in France and elsewhere.
Other Senate Democrats said they also would defend Obama's immigration moves, and Republican House Speaker John Boehner declined to say how Republicans would proceed.
"The goal here is not to run DHS out of money. The goal is to stop the president's overreach," Boehner told a news briefing.
Asked if he would support another short-term funding extension for DHS, Boehner said: "Why don't we wait until the United States Senate acts? And then we can decide what the next steps are."
Republicans were divided on their response. Some, including Representative John Carter of Texas, who chairs the House Appropriations Homeland Security subcommittee, said they would prefer a "clean" DHS bill to leaving the agency short of funds.
But conservative Raul Labrador of Idaho said it was important to continue the fight against Obama on immigration, even if it means a lapse in DHS funds. He said Obama would take the blame, not Republicans.
"If the president's willing to do that, that would be on the president," Labrador said.
While much of DHS' security functions have been deemed essential and will continue to operate if funding lapses, the agency has said it would be forced to furlough about 30,000 employees, or 15 percent of its total.
(Additional reporting by Julia Edwards; Editing by John Whitesides and James Dalgleish)