The government yesterday abandoned its efforts to stop the Progressive magazine from publishing an article about the hydrogen bomb because the basic secrets underlying the dispute have already been made public.

The Justice Department said the case against the Progressive had been made moot by publication of a lengthy letter Sunday in a Wisconsin newspaper, the Madison Press Connection.

Officials at Justice said they now intend to determine whether to bring criminal charges as a result of the newspaper's action.

First, however, the government will ask for dismissal of temporary restraining orders issued by federal judges against both the Progressive and the Daily Californian of Berkeley.

Justice Department spokesman Terrence Adamson said the decision was made by Acting Attorney General John Shenefield in light of the letter in the Press Connection "containing restricted data concerning thermonuclear information."

The letter, written by computer programmer Charles Hansen of Mountain View, Calif., "substantially exposed" the three critical concepts about the making of a hydrogen bomb that the government was trying to protect, Adamson said. The action by the Madison paper effectively declassified the "secret restricted data" in the letter, he added.

This lifts the legal restrictions preventing the Progressive and other publications from printing such articles about the H-bomb, Adamson said.

The department's criminal division will now start a preliminary inquiry to determine whether to prosecute anyone for violations of the Atomic Energy Act -- which prohibits dissemination of classified nuclear information -- or of the court order in the Progressive case.

The government moved against the Progressive last March -- the first time federal officials have tried to prevent an American journal from publishing. A U.S. district court judge imposed a temporary restraining order through the magazine's lawyers argued that the planned article by freelance writer Howard Morland was derived solely from material in the public domain.

Adamson refused to say yesterday whether the department believes there were leaks from the secret briefs that were subsequently filed in the Progressive case. But other department officials said there were similarities between the Morland article and articles published last spring by the Milwaukee Sentinel. There were also similarities between the Morland piece and the Hansen letter published Sunday by the Madison paper, they said.

Adamson said the government feels national security has been harmed by publication of classified nuclear material. He said the release "significantly increase" the chance of the spread of nuclear weapons.

"We're going to continue to try to uphold" the principle of stopping the spread of such information, he said. "In this particular effort we have been thwarted."

Adamson said the government had already filed a motion to dismiss the suit filed late Saturday against the Daily Californian, which was one of several papers that received Hansen's letter. A federal judge in San Francisco dismissed that suit later in the day. A similar motion with the Seventh U.S. Circuit Court of Appeals in Chicago would dismiss the case against the Progressive.

The circuit court panel which is considering the Progressive's appeal of last March's restraining order put the government on notice earlier yesterday that it questioned whether the case was still valid. It did so by ordering government attorneys to file a memo about the effect on the Progressive case of articles published between Aug. 30 and Oct. 1.

On Aug. 30, the Peninsula Times Tribune of Palo Alto, Calif., published a summary of the 17-page Hansen letter, including a diagram.

Then, last Wednesday, Sept. 12, Energy lawyers told Hansen that both his letter and the diagram, which was said to illustrate an H-bomb cross-section, had been classified under the secrecy provisions of the 1954 Atomic Energy Act.

The letter by computer programmer Hansen had been dated Aug. 27, addressed to Sen. Charles Percy (R-Ill.) and sent to a number of politicians and publications.

After Hansen was contacted by DOE officials last week, he surrendered his remaining copies and the government got a list of his addressees.

Officials would not comment on whether the Peninsula Times Tribune was also part of the preliminary criminal investigation.

The editor of the Press Connection, Ron McCrea, said in a phone interview yesterday from Madison that "if they turn their legal guns on us, so be it. We were aware of the possible consequences of publishing the letter. We verified that he used no classified sources in preparaing the letter. We're fighting his ridiculous retroactive classification system."

McCrea said that he did not have a lawyer but has been told the American Civil Liberties Union was standing by to represent his paper. The Press Connection was founded in 1977 by striking editors and reporters in Madison.

The government's fight to prevent disclosure of the purported secrets of the H-bomb has been troubled from the beginning. Justice Department lawyers on the case reportedly recommended months ago that it be dropped because of disclosure that the same kind of classified information had been on the shelves of the government's atomic energy library in Los Alamos, N.M. Several prominent scientists also said that the fathers of the H-bomb had already published articles about its key concepts in widely used encyclopedias.

Ira Glasser, of the American Civil Liberties Union, which represented the Progressive in court, expressed pleasure last night that the magazine finally will be able to publish.

"The government tried to censor political ideas and it succeeded for nearly six months," he said. "This case proved again the wisdom of the First Amendment and the skepticism we should all have whenever the government make claims of national security."