President Carter's announced "inclination" to prosecute Ramsey Clark and nine other Americans who defied his order to stay out of Iran set off charges yesterday that he was chilling the exercise of constitutional rights, applying an emergency law improperly, and clouding the Justice Department's independence.

Perhaps ironically, he also was accused of jeopardizing the very prosecution he seeks by making it possible for the prospective defendants to allege unfair treatment.

The charges were made in statements and interviews by sources including an expert on constitutional law, the American Civil Liberties Union, and Clark, himself a former attorney general.

Others, including leading Republicans, have been clamoring for strong action. They say that Clark and his associates not only defied the president but insulted the United States in Iran, which still holds 53 Americans hostage.

By contrast, Attorney General Benjamin R. Civiletti was walking a straight and narrow public path yesterday. He says that "regular litigation standards" -- not the inclination of the president at whose pleasure he serves -- will determine whether a criminal or civil action will be brought under the International Emergency Economic Powers Act of 1977.

In a televised exchange in Baltimore carried by NBC, a reporter asked him, "Is there any concern that the president's remarks might have prejudged the case and that could be a problem in the prosecution if you do it?"

"I don't think so at all," Civiletti replied. "I think [the remarks] were not . . . made as directions or as any convictions of guilt whatsoever.

"I think it was a circumstance where someone popped a question to him during the plane trip and he just reacted in a . . . personal way with his feeling about his reaction to the public acts which have been printed in the papers."

White House press secretary Jody Powell, meanwhile, said that Carter was not trying to pressure the Justice Department. But "the president has constitutional and ultimate responsibility to make sure the laws of this country are faithfully enforced," Powell said.

For now, however, the ball is in the Treasury Department's court. Its Customs Service is investigating the posibility of a violation of an April 17 presidential order interpreting the 1977 law to forbid Americans to engage in "any" financial transactions -- involving transportation and even meals and lodging -- in connection with travel to and within Iran.

Last night, Treasury said it will be sending its findings to the Justice Department "over the next couple of weeks." Only after the findings are in hand, Civiletti has said, will a decision be made as to whether to bring a complaint.

Until Carter disclosed his inclination to reporters aboard Air Force One Tuesday, he had taken a dim view of restrictions on the freedom of Americans to travel.

He himself noted that in March 1977 he had lifted restrictions imposed, starting in the 1950s, on travel to Cuba, Vietnam, Cambodia and North Korea because of his concern that they might violate human rights as defined in the so-called Helsinki Agreement of 1975. Then he said:

"So we have done everything we could to legalize travel when we thought that the travelers would be safe and . . . that there was nothing that they would be likely to do that would be contrary to the security interests of our country."

The Clark group disregarded a new State Department rule requiring that it validate passports specifically for travel to Iran. But such rules have been disregarded in the past without retribution. In 1967, the Supreme Court, striking down an indictment of 58 Americans who went to Cuba without endorsement of their passports for the trip, said they hadn't committed a criminal offense.

Constitutional scholar Laurence H. Tribe of Harvard, accusing Carter of "a terrible blunder," said it would have been "permissible" for him to say he was asking the Justice Department to investigate the possibility of a law violation as opposed to saying he was inclined to favor a criminal or civil proceeding.

Tribe could cite no parallel for the president's remarks. In 1970, President Nixon said that cult leader Charles Manson was "guilty, directly or indirectly, of eight murders." But his aides swiftly indicated that Nixon had not intended to presume Manson's guilt. In addition, it was the state of California, not the federal government, that had jurisdiction.

Tribe, in a phone interview, said that it's a "perversion" of the 1977 law "to stretch it to deal with . . . political travel, and that it's a perversion aggravated by the president's remarks."

Tribe said that constitutional rights also are at stake.In a separate opinion in a 1964 case, the late Justice William O. Douglas wrote, "Free movement by the citizen is of course as dangerous to a tyrant as free expression of ideas or the right of assembly . . . That is why riding boxcars carries extreme penalties in communist lands."

Several lawyers voiced doubts that the government could survive a First Amendment test or regulations that permit news organizations, but not private citizens, to travel to and inside Iran and to engage in financial transactions there.

During the 1976 presidential campaign, Carter said the attorney general "must be removed from politics and given the full prerogatives, independence, and authority of his or her own office."

Tribe said, however, that "the Justice Department's independence can't be taken seriously if the president makes casual comments to the press about individuals he would like to see prosecuted."

The civil liberties union said that, in trying to "prejudge" the case, Carter had displayed an "ignorance of basic constitutional standards" matched only by Nixon's.