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House Speaker Dennis Hastert accused the Justice Department Thursday of trying to intimidate him in retaliation for criticizing the FBI's weekend raid on a congressman's office, escalating a searing battle between the executive and legislative branches of government.

"This is one of the leaks that come out to try to, you know, intimidate people," Hastert said on WGN radio Thursday morning. "We're just not going to be intimidated on it."

The Illinois Republican, in his interview with a Chicago radio station, was responding to an ABC News report that quoted an unnamed law enforcement source as saying that he was "in the mix" of the Justice Department's investigation into influence peddling by convicted lobbyist Jack Abramoff.

Within minutes of that report late Wednesday, the department issued the first of two denials that it was investigating Hastert. The speaker demanded a retraction from ABC News, which refused. Hastert on Thursday threatened to sue the network and reporters and executives for libel and defamation.

"We will take any and all actions necessary to rectify the harm ABC has caused and to hold those at ABC responsible for their conduct," wrote Hastert's counsels, J. Randolph Evans and Stefan C. Passantino. The letter was addressed to network President David Westin reporter Brian Ross.

Hastert aimed his broadsides at the Justice Department amid a swirl of recriminations on Capitol Hill, including warnings by some lawmakers of a voter backlash against members of Congress "trying to protect their own."

Hastert's aides, at the same time, were in talks with the White House about the possible transfer of material seized by the FBI during its weekend raid of the office of Rep. William Jefferson, perhaps to the House ethics committee, according to several Republican officials.

The goals of any transfer, they said, would be to deny the documents both to prosecutors and to Jefferson, a Louisiana Democrat ensnared in a bribery investigation, until the legal issues surrounding the weekend search of his office are resolved. The officials spoke on condition of anonymity, citing the confidential nature of the discussions.

The confrontational approach by Hastert and the House Democratic leader, Nancy Pelosi, did not sit well with some colleagues.

"Criticizing the executive and judicial branches of our government for fully investigating a member of Congress suspected of criminal wrongdoing sends the wrong message and reflects poorly upon all of Congress," Rep. Barbara Cubin, R-Wyo., said in a statement. "They should not expect their congressional offices to be treated as a safe haven."

A GOP colleague, Sen. David Vitter of Louisiana, said the public "will come to one conclusion: that congressional leaders are trying to protect their own from valid investigations."

While some lawmakers contended the executive branch overstepped its authority, Senate Democratic leader Harry Reid of Nevada has declined to condemn the search.

"I'm not going to beat up on the FBI," said Reid, a frequent critic of the White House's use of executive power.

Their voices were in the minority on Capitol Hill in the wake of the 15-hour search during which agents collected evidence against Jefferson, an eight-term Democrat.

Historians said it was the first such search of a congressman's quarters in the more than two centuries since the first Congress convened.

Deputy Attorney General Paul McNulty said the raid was lawful and necessary. Justice Department officials have said Jefferson had refused to cooperate with the investigation.

The White House continued to try to keep its distance publicly. "We acknowledge the constitutional concerns of the House of Representatives and we also acknowledge the law enforcement obligations of the executive branch," White House press secretary Tony Snow said. "We hope that the two sides are going to be able to work this out."

In their rare joint statement, Hastert and Pelosi demanded that the FBI return the documents and that Jefferson then would have to cooperate with the investigation.

As evidence of Pelosi's lack of support for her fellow Democrat, she said he should step down from the powerful House Ways and Means Committee.

Jefferson filed a motion Wednesday asking the judge who signed the search warrant to force the FBI to return the seized items.

The congressman has refused to step down from the tax-writing committee and has acknowledged no wrongdoing.

Pelosi's curt letter to Jefferson, and the public nature of it, has riled a sizable bloc of her House troops -- the 42-member Congressional Black Caucus. At private meetings with and without Pelosi on Wednesday, members of the group grew emotional and complained that Jefferson was being singled out.

They noted that another member under investigation, Rep. Alan Mollohan, D-W.Va., was forced to step aside as ranking member of the Ethics Committee but was allowed to keep his seat on the Appropriations Committee.

"I have an excellent relationship with most" members of the CDC, Pelosi told reporters Thursday.

The House Judiciary Committee chairman, GOP Rep. James Sensenbrenner of Wisconsin, announced a hearing next week, "Reckless Justice: Did the Saturday Night Raid of Congress Trample the Constitution?"

But Vitter released a letter to his own GOP Senate leaders asking them to stop saying that the FBI raid violated the Constitution.

"For congressional leaders to make these self-serving arguments in the midst of serious scandals in Congress only further erodes the faith and confidence of the American people," Vitter wrote.

The Associated Press reported last November that Hastert for two years did not disclose his use of Abramoff's restaurant for a fundraiser just two weeks before he asked the Interior Department in a letter to reject a Louisiana Indian tribe's application for a casino license.

At the time, Abramoff was representing another tribe that opposed the casino. Hastert, who collected a total of $100,000 from Abramoff's and his tribal clients, blamed a paperwork oversight, filed the required disclosure and paid for the use of the restaurant.