Watchdog groups are bracing for a last-minute House GOP parliamentary maneuver that could hamper passage of a measure creating an outside ethics office that has been nearly a year in the making.

Republican members of a bipartisan House ethics task force, which has been working on the issue since last March, have remained mum on whether they support the proposal to change internal House rules. Other Republicans not on the task force have privately blasted provisions of it, arguing that aspects of the new Office of Congressional Ethics (OCE) would subject members to political witch hunts and create a “star chamber” in the House.

Floor maneuvers could be tricky for Democrats, Republicans and outside watchdog groups that support the bill but would like to see improvements. Democrats have to worry about opposition to the bill from their own caucus, while the GOP must worry about how its actions will be perceived in the wake of the indictment last week of Rep. Rick Renzi (R-Ariz.).

A spokesman for Boehner played his cards relatively close to the vest, but indicated displeasure with the process leading up to the vote.

“For much of last year we worked with Democrats in a bipartisan way to fix the ethics process,” said Boehner spokesman Michael Steel. “The Democrats walked away from that effort. We will continue to look for ways to improve this legislation.”

Majority Leader Steny Hoyer (D-Md.) said Tuesday that Democrats would not allow amendments on the resolution because it involves a change to a House rule. Traditionally, amendments have not been considered on such resolutions.

Democratic leaders also rejected any accusation that their members walked away from the bipartisan negotiations on the task force.

“This has been a bipartisan process and has been in the works for more than a year,” said Nadeam Elshami, spokesman for Speaker Nancy Pelosi (D-Calif.). “There is broad support for this — not just in the Democratic Caucus but with outside organizations and the public.”

Floor strategies are somewhat complicated by the fact that some Democrats oppose the measure. Although it is expected to pass with bipartisan support, this Democratic opposition gives any Republican parliamentary maneuver a chance of succeeding. A GOP effort to use a parliamentary maneuver to force the Democrats to vote on the Foreign Intelligence Surveillance Act failed Tuesday on a vote of 212-198.

About 40 Democrats either opposed the bill, were undecided or did not respond to a whip notice on the ethics resolution sent last Friday, including several members of the Congressional Black Caucus, according to a Democratic source tracking the resolution’s support.

Opposition in some Democratic circles is fierce.

“The people who are guilty of committing crimes are serving time in jail right now,” said Rep. Gregory Meeks (D-N.Y.). “There’s a real fear of witch hunts, and black legislators have been unfair targets of that in the past.”

Watchdog groups, including those that wholeheartedly support the legislation and others that have pushed for stronger investigative powers for the outside ethics entity, are concerned that Republicans may try a procedural move that would allow them to gain floor control from the Democrats. If that happens, any member, Republican or Democrat, could offer “poison pill” amendments that could sink the measure.

U.S. PIRG’s Gary Kalman, who is urging members to support the bill, said lawmakers have told him hat some Republicans may try to attach an earmark reform proposal to the bill, which would be difficult for his group to oppose. Republicans, he said, also are discussing amendments that would grant the office more investigative tools such as subpoena power, which several prominent watchdog groups have argued is essential for the office to make any improvements to the ethics process.

“That would be killing the bill with kindness, so to speak,” Kalman said.

Kalman said his group would support an effort to add an earmark reform provision to the measure only if Republicans were sure it had enough votes to pass and the measure would not end up sinking the overall legislation.

“This ethics enforcement proposal has been a year in the making and we need to give this a fair shot on the floor to make sure we can change the ethics process,” he said.

Two freshman Democrats who had mulled offering an amendment giving the OCE subpoena power have abandoned that idea out of concern that they wouldn’t have the votes to succeed and would therefore cloud the Democrats’ ability to tout the overall bill as a success when it passes, sources said.

“I spoke to the freshmen the week before we left for recess and they seemed to be fine with it,” said Rep. Michael Capuano (D-Mass.), who chaired the ethics task force and is spearheading the effort to move it on the floor.

He would not say whether freshman Democratic Reps. Chris Murphy (Conn.) or Zack Space (Ohio), the two members who wanted the office to have subpoena power, attended his meeting with freshmen.

Rep. Christopher Shays (R-Conn.), a longtime advocate of tougher ethical standards for members of Congress, is readying an amendment to grant the ethics office subpoena power. But he could only offer it if Republicans were successful in gaining control of the floor.

Republican leaders trying to convince Renzi to resign, however, may have a tough time explaining any kind of parliamentary maneuver designed to defeat the resolution.

Capuano said Republicans should offer proposals through the normal legislative channels “if they want to have a legitimate discussion and debate” on earmark reform. He said it would be obvious that tricky procedural proposals are designed to “obfuscate and change the subject.”

Even watchdog groups that aren’t backing the resolution because they don’t believe it is strong enough will take a dim view of any GOP effort to derail it.

“I for one would just look at it as a smokescreen,” said Meredith McGehee of the Campaign Legal Center. “On a week that Rick Renzi is indicted and they’re trying to boot him out of Congress, how can they say that we want less ethics scrutiny?”