Sen. Russ Feingold (D-Wis.) held out the possibility Thursday afternoon that he would block quick passage of any changes to warrantless wiretapping laws, despite enormous pressure from both the Democratic and Republican leadership to approve a bill by Friday at the latest so Congress can leave town for the monthlong August recess.

Saying Congressional Democrats and Republicans were moving “awfully quickly” on a White House proposal to make it easier to eavesdrop on suspected overseas terrorists, Feingold said he is in “no hurry” to leave town for the August recess.

“I don’t feel the need to get out of here. I would much rather stay here than have us make a terrible mistake,” said Feingold, who has made a name for himself as a champion on civil liberties in the Senate. “This is not the kind of thing that should be done on the fly, and I am prepared to stay here as long as it takes to fix it. Or, if they need force this through, I’m not going to make it easy, if they don’t make it better.”

Asked whether he would attempt to filibuster any bill that comes up prior to the Senate’s adjournment for the August recess, Feingold said he would prefer to be able to give his stamp of approval to the measure.

“But at the moment I’m feeling a little worried that that isn’t going to be possible,” he said. “It’s not moving in the direction that I’m hoping, but I think it might be moving in the wrong direction, in which case the options have to be potentially utilized.”

Meanwhile, Senate Intelligence Chairman Jay Rockefeller (D-W.Va.) said Thursday afternoon that he was “in the thick” of negotiations with the White House and Republicans over how to change current law so that intelligence operatives can surveil overseas targets whose communications pass through U.S. networks without first obtaining a warrant. While both Democrats and Republicans generally agree that those barriers in current law need to be lifted, they have been stymied by who should oversee such activities — with Democrats balking at the notion of giving embattled Attorney General Alberto Gonzales sole authority over the program.

The White House’s latest offer — to give both Gonzales and National Intelligence Director Michael McConnell oversight authority — has been met with skepticism by most Democrats involved in the talks. Democrats have proposed allowing a Foreign Intelligence Surveillance Act court to oversee the attorney general’s activities, as well as a six-month sunset provision.

Still, both Rockefeller and Senate Majority Leader Harry Reid (D-Nev.) said they hoped to have a deal Thursday night.

At a Thursday press conference, Reid said he has been in contact with Speaker Nancy Pelosi (D-Calif.) about how to move any compromise quickly through both chambers.

“We’re doing our very best to get something,” Reid said. “But we’re not going to be stampeded.”

Feingold said anything that passes quickly this week should sunset in September, and he said Rockefeller’s proposal is not adequate to protect the civil liberties of innocent Americans whose communications may be intercepted in the quest for terrorist messages.

“The protections related to that are not adequate — not that I’ve seen,” Feingold said. He added, “There are also other issues that relate to my desire to reaffirm the fact that the FISA statute is the exclusive means for wiretapping. That should be reaffirmed. I think that should be in there.”