Alarmed by what they consider the repressive scope of a new CIA secrecy bill, senior Democrats on the House Judiciary Committee have joined in a last-ditch effort to curtail it.

Chairman Peter W. Rodino Jr. (D-N.J.) and other ranking committee members believe the measure to be unconstitutional, but recognize that it has formidable support.

The bill would make it a crime to disclose any information, even if obtained from unclassified sources, that serves to identify CIA officials or any other U.S. intelligence operative who has been working abroad.

In a letter sent to other committee members recently, Rodino and five other senior Democrats on the panel protested that the bill could outlaw the revelation of a wide range of CIA misdeeds.

Had it been in force at the time of the Watergate break-in, Rodino and the others argued, it could have prevented investigation and disclosure of the CIA connections of some of the Watergate burglars.

Already approved in slightly differing versions by the House and Senate Intelligence committees, the bill is aimed in large measure at suppressing anti-CIA periodicals such as the Covert Action Information Bulletin, which regularly prints the names of CIA officers on overseas assignment.

The stiffest penalties in the bill -- 10 years in prison and a $50,000 fine -- are reserved for past and present government officials who learn the identity of covert agents in the course of their work.

But to outlaw publications such as the Covert Action Information Bulletin, the bill would permit the prosecution of any journalist or other "outsider" who discloses the name of a secret operative "with the intent to impair of impede the foreign intelligence activities of the United States." Such offenses would carry a maximum penalty of three years in prison and a $15,000 fine.

This is the section that Rodino and his allies -- Reps. Don Edwards (D-Calif.), Robert W. Kastenmeier (D-Wis.), John F. Seiberling (D-Ohio), Robert F. Drinan (D-Mass.) and Elizabeth Holtzman (D-N.Y.) -- are fighting as unconstitutional. They say it would even have criminalized disclosure of the CIA's campaign years ago to destabilize the government and economy of Chile.

Claiming that the real problem was "that disclosure of sensitive government information based on privileged access . . . by faithless government employes," they said the bill should be restricted to unauthorized disclosures by past and present government officials.

But beyond that, they maintain, it is the job of the CIA and the president to keep the names of covert agents out of public records, such as old State Department Biographic Registers.

"Criminalizing disclosures stemming from sloppy secrecy procedures," they said, "will only tend to lull the agency into inaction. Surely if private citizens have been able to infer identities from public sources, so, too, has the KGB," the Soviet secret police.

So far, however, the tide has been running in favor of the more sweeping proposal. It has the support not only of congressional Republicans but also of prominent Democrats, such as House Majority Leader Jim Wright (D-Tex.), and House Intelligence Committee Chairman Edward Boland (D-Mass.).

Much of the impetus for it came from July 4 machine-gun attack on the home of the CIA station chief in Jamaica, whose name had just been disclosed by a Covert Action editor.

Edwars, however, has voiced doubts that Congress can draft a bill "criminalizing disclosure of already public information without running afoul of the First Amendment."

Despite a boycott by GOP members, Edwards' House Judiciary subcommittee on constitutional rights voted 5 to 1 last week to restrict the penalties in the bill to past and present government officials. The full committee, which must report the bill out by midnight Wednesday or face loss of jurisdiction over it, will meet tomorrow morning to take it up.

There were rumors over the weekend that the Republicans might boycott the Wednesday session in hopes of deying it a quorum and preventing any action. But Rep. Robert McClory (R-Ill.), the ranking minority member on the full committee, said he knew of no such plan. He said he thought that proponents of the original bill had enough votes to restore the penalties for journalists.

"I'll be there and so far as I know, the other Republicans will be there," McClory said of Wednesday's meeting. "We're planning to take a strong stand. So are a number of the Democrats. After all, it's Eddie Boland's bill."