A conservative group launched a $3.3 million campaign to end judicial filibusters Monday, becoming the first activists on the right to fire a multimillion-dollar shot this year in the long-running battle over confirming President Bush’s judges.

Progress for America, a 527 group that counts several advisers close to both the White House and Senate Majority Leader Bill Frist (R-Tenn.), announced its intention to target up to 10 Senators as they are home this week for recess.

The effort comes just weeks, if not days, before an expected showdown over judicial confirmations known as the “nuclear option.”

Seeking to apply pressure to wavering Republicans and Democrats who represent conservative states, Progress for America’s campaign mixes TV and radio ads boasting of the credentials of two of the nominees close to the center of the debate: California Supreme Court Justice Janice Rogers Brown and Texas Supreme Court Justice Priscilla Owen.

“Our effort today is to personalize” Brown and Owen, said Brian McCabe, president of the organization, which files under Section 527 of the IRS code.

Several liberal groups have already been on the air for weeks with advertisements that have cost up to $10 million.

As the latest shot in its own $5 million campaign, People For the American Way debuted its own ad Monday, specifically targeting the nominations of Brown and Owen because of their “radical judicial philosophies.”

Other groups that have taken to the airwaves to attack Bush, Frist and Vice President Cheney in advance of the nuclear option include the Alliance for Justice and MoveOn.org’s political action committee.

By contrast, conservative groups have been far more tight-fisted with their resources thus far, with some husbanding cash for a likely Supreme Court nomination battle later this summer.

And some conservative activists privately contend that this issue is too complex for 30-second sound bites geared toward middle-of-the-road voters. Instead, some strategists believe the issue plays out better in radio and e-mail pieces designed to specifically target base voters.

The Judicial Confirmation Network did a small TV buy in support of Frist’s move to end the filibuster, and the Family Research Council has weighed in with a round of newspaper ads and some radio.

Until now, Progress for America had not been a major player on the judicial battles, instead focusing much of its financial muscle on the battle over Social Security. Their move into the judicial air wars is just the latest sign that the final battle over the rules of judicial confirmation could be at hand this month.

Last week, each side appeared to harden its position against compromise, refusing to yield on the one critical element at the center of the debate.

Democrats offered a compromise allowing some previously filibustered nominees to win approval, but they reiterated that they will not give up their right to demand a 60-vote threshold for cloture for “extraordinary” nominees.

In the meantime, Republicans offered a compromise that would have ensured that future nominees do not get bottled up in committee — a fate that befell many of then-President Bill Clinton’s appointees during the 1990s. But the GOP refused to yield on its main contention that all judicial nominees must ultimately face a vote that requires just 51 votes for confirmation.

With no compromise in sight, a senior Frist aide told reporters last week, “Soon now, all 100 Senators will have to decide.”

An adviser to Progress for America dismissed some newspaper polls showing displeasure with ending filibusters on judicial nominees, noting that support rises or falls by as much as 40 points depending on the question’s wording. Moreover, he suggested that the liberal groups have had more luck pushing their side of the story because of media bias.

“They may have a more sympathetic megaphone to talk through,” said Ben Ginsberg, a legal adviser to Progress for America.

Like other advisers to the group, Ginsberg’s GOP bona fides are strong. He served as counsel to the Bush-Cheney campaigns in 2000 and 2004 and as an outside counsel to the National Republican Senatorial Committee in 2002 when Frist was its chairman.

Much of the media work for the group is done by DCI Group, with the Progress for America account headed by Stuart Roy, the former communications director for House Majority Leader Tom DeLay (R-Texas). Roy was also communications director for the NRSC during the 2000 cycle, when current Senate Majority Whip Mitch McConnell (R-Ky.) chaired the GOP’s campaign arm.

Handling press operations inside Progress for America is Chris Myers, a former communications aide for Senate Republican Conference Chairman Rick Santorum (Pa.).

Also on hand at Monday’s launch was C. Boyden Gray, the founder of another organization that is promoting Bush’s nominees, the Committee for Justice. Gray was White House counsel under President George H.W. Bush.

Despite such connections to the White House, the conservative activists said they had no precise knowledge of when the fight over the judicial process would erupt, and they added that they had no inside information that it would commence with either Brown or Owen.

The ad campaign this week is targeting six states — Alaska, Arkansas, Maine, Nebraska, North Dakota and Rhode Island — each with at least one Senator who could prove decisive if the issue comes to a final vote.

In particular, Sens. Lisa Murkowski (R-Alaska), Susan Collins (R-Maine) and Olympia Snowe (R-Maine) have refused to be pinned down on how they would vote if Frist forces a floor vote on procedurally ending filibusters.

Just two Republicans — Sens. John McCain (Ariz.) and Lincoln Chafee (R.I.) — have announced their intentions to oppose the move. Democrats would need to peel off four more Republicans to prevail in a floor fight.

The PFA ads, which were produced by McCarthy Marcus Hennings Ltd., will begin airing nationally next week when the Senate returns.

McCabe said the financing for the ads came from general solicitations and was not part of a specific fundraising drive on this one issue.