Republican lawmakers pressed ahead Thursday with plans to charge Attorney General Eric Holder with contempt of Congress for refusing to turn over documents on a failed gun-tracking operation even as Democrats accused Republicans of harassing the attorney general just to prevent him from disrupting their plans to suppress the vote in November.

"It is no coincidence that the attorney general of the United States is the person responsible for making sure that voter suppression does not happen in our country, that issues that relate to the civil liberties of the American people are upheld," House Minority Leader Nancy Pelosi, D-Calif., said. "These very same people who are holding him in contempt are part of a nationwide scheme to suppress the vote."

Republicans, meanwhile, suggested that President Obama's assertion of executive privilege to prevent them from seeing the documents on the Fast and Furious operation may be part of a White House cover-up.

"The decision to invoke executive privilege is an admission that White House officials were involved in decisions that misled the Congress, and have covered up the truth," House Speaker John Boehner charged.

A House committee on Wednesday voted to find Holder in contempt of Congress for refusing the turn over of documents related to Fast and Furious, an operation in which the U.S. allowed American guns to be moved into Mexico in hopes of tracing them to drug cartel leaders. Several guns turned up later at crime scenes and one was used to kill a U.S. border agent.

Boehner, R-Ohio, promised a vote on the contempt charge next week in the full House, which is controlled by Republicans.

The White House denied Republican charges of a cover-up. Spokesman Jay Carney said Obama's use of executive privilege to protect the Justice Department documents from congressional scrutiny was appropriate. The department already turned over 7,600 documents. Besides, Carney said, Fast and Furious began under President George W. Bush.

"Yet, Republicans insist on moving forward with an effort that Republicans and objective legal experts have noted is purely political," Carney said.

Pelosi's accusations about voter suppression stem from an ongoing battle that has nothing to do with Fast and Furious. Holder last week sued to stop Florida, under the direction of Republican Gov. Rick Scott, from purging names from voter rolls. Florida officials said they only want to delete those who are dead or here illegally.

Holder contends Florida is using outdated information that would cause legitimate voters to be purged from the rolls.

Florida, a perennial swing state, is considered one of the most pivotal contests in November's presidential election. Obama won the state in 2008 with 51 percent of the vote. In 2000, George Bush won Florida, and thus the presidency, by just 537 votes.

Boehner, responding to Pelosi's accusation, said Congress is obligated to investigate Fast and Furious, which resulted in the death of border agent Brian Terry.

"Listen, the American people deserve the truth about what happened in Fast and Furious," Boehner said. "The Terry family deserves answers about why their son was killed as a result of an operation run by the United States government."