The legal briefs defending the new campaign finance reform law were kept under seal or heavily redacted by their sponsors yesterday, as the groups battling to preserve the McCain-Feingold bill were forced to observe a court order that keeps much of the evidence of alleged campaign excesses from public view.

The Justice Department, the main defender of the Bipartisan Campaign Reform Act, kept its pleadings sealed, and the congressional defenders of the measure released a 143-page redacted version of their brief, a sealed version of which ran 158 pages. The sealed versions were filed late Wednesday to a three-judge federal panel in U.S. District Court in Washington.. The plaintiffs also issued redacted versions of their briefs, but they cited less sensitive material, so not as much was omitted.

But with a court hearing in the landmark case a month away, lawyers representing the members of Congress who support the bill moved to make the documents open to the public, hoping to eliminate secrecy from the hearings.

"We see no basis for the information that we have in our briefs as being entitled to confidentiality," said Fred Wertheimer, a lawyer on the defense team and president of Democracy 21, an advocacy group that lobbied for the legislation. "It doesn't meet the tests or standards that keeps material confidential in commercial litigation regarding trade secrets or competitive practices."

The sealed documents stem from an Aug. 13 protective order issued by the three-judge panel. Any of the 100 or so people giving depositions could declare all or part of their testimony to be "confidential," meaning it couldn't be made public, or "highly confidential," meaning not even all lawyers in the case could see the material.

The protective order was designed to help witnesses feel free to discuss the delicate issues of "soft money," campaign financing and political strategy. But now that the case is headed for court, attorneys defending the new law want to use the most glaring examples of excesses as reasons the new law -- which greatly curbs soft, unregulated campaign contributions -- should be upheld.

The public versions made available yesterday offered only suggestions of what was filed to the federal panel.

"When elected officials raise soft money, the tie between soft money and pending legislation is not left to the imagination. Here is an example of [REDACTED," says one passage of the brief filed by congressional sponsors.

"Or take the example of [REDACTED]," the next line says. In some of the depositions, the redacted words are blacked out.

Most of the barred material comes from documents or testimony filed by the Republican National Committee, one of the more than 80 plaintiffs seeking to have the law declared unconstitutional, that details spending by the party and sympathetic groups during campaigns.

As defense attorneys circulated an e-mail requesting a meeting with plaintiffs next week to discuss making all material in the briefs public, one of the lawyers defending the RNC, Bobby R. Burchfield, said he was open to the request.

"We're going to contact the people involved, most of whom are not RNC members but are third parties, and see if they don't mind," he said. "Under the protective order, we have to treat it that way."

He did acknowledge that some of the campaign financial numbers might be kept secret, "because to put out the Victory Plan of the RNC in a particular state will tell the opposition more than RNC feels comfortable with."

Trevor Potter, one of the members of the defense team, said the issue was more clear cut.

"There's only one reason to keep it confidential, and that's because it doesn't reflect well on them," said Potter. "The parties bend, stretch and twist the law to get these donations. They'd rather the press not know that."

The campaign law's defenders in Congress released a 143-page redacted version of their brief. The plantiffs also released a version.