In their latest effort to force federal wiretapping legislation favored by the Bush administration onto the House floor, Republicans are pressing conservative Democratic lawmakers to sign onto a discharge petition.

Rep. Vito Fossella (R-N.Y.), along with Republican Reps. Lamar Smith (Texas), Pete Hoekstra (Mich.) and Peter King (N.Y.), introduced the discharge petition Wednesday, which counted more than 100 signatures — all from GOP lawmakers — by early evening.

But GOP lawmakers hope to add the signatures of members of the Democratic Blue Dog Coalition, many of whom represent conservative-leaning districts and have previously endorsed the legislation expanding the warrantless wiretap program.

“This is an opportunity for the 21 Blue Dog Democrats who signed a letter supporting the bipartisan, Senate-passed FISA bill to prove that they are serious about America’s national security,” said Michael Steel, House Minority Leader John Boehner’s (R-Ohio) spokesman. “Will they choose to protect their constituents or will they back the Democratic leadership in kowtowing to trial lawyers and liberal special interests?”

The petition, which would require 218 signatures to succeed, would force a Senate-approved measure to expand the Foreign Intelligence Surveillance Act to the House floor.

Democratic House leaders have strenuously opposed that legislation, however, over objections to provisions — stipulated by President Bush and Congressional Republicans — that would provide retroactive immunity provisions for telecommunications companies that aided the Bush administration in warrantless wiretapping.

The House approved its own version of the warrantless wiretap program in March after weeks of negotiations with the Senate faltered. That bill eliminated those immunity provisions and instead provided for secure proceedings for telecom companies to defend their actions in court, and to allow the judicial branch to address pending lawsuits.

While that vote provided political cover to conservative Democrats, one senior Blue Dog lawmaker, who spoke on the condition of anonymity, acknowledged that some of the coalition’s freshmen may be compelled to sign the discharge petition.

“A lot of them feel a lot of political pressure from the right to go with the president’s position,” the Democratic lawmaker said.

But the Blue Dogs will make a concerted effort to sway their members from signing the discharge petition.

“It’s a tactic of the minority to gain control of the floor,” the Democratic lawmaker said. “We will talk to our folks as much as we can about what a discharge petition is and what it does.”

Although negotiations between the White House, House and Senate have resumed, an agreement has remained elusive.

But House Majority Leader Steny Hoyer (D-Md.) expressed optimism Wednesday that an agreement could be reached before the Memorial Day recess in late May.

There has been movement. We have been moving forward,” Hoyer said. “I think good discussions are going on.”