In Washington, a city of lawyers, the lawyers now have something else to worry about.

Prominent congressmen are claiming that the attorney-client privilege is not available before Congress as a matter of right, but that its applicability depends on the discretion of the committee involved.

According to this view, if a committee so decrees, a lawyer can be forced to disgorge the secrets his client tells him. A client can be compelled to reveal the advice his lawyer gives him.

Alarmed by this position, two congressmen, Mervyn M. Dymally (D-Calif.) and Gerald B. Solomon (R-N.Y.), introduced legislation to establish that the attorney-client privilege is available before Congress as a matter of right.

These congressmen recognize that if the applicability of the attorney-client privilege is left to the discretion of legislators, clients will be chary of telling their lawyers the truth. This result, the Supreme Court recently has noted, would impede the observance of law and the administration of justice.

A little recent history will put the current controversy into better focus.

On Dec. 12, the House subcommittee on Asian and Pacific affairs, which is chaired by Rep. Stephen Solarz (D-N.Y.), voted contempt citations against a New York attorney and his brother (who had worked for the attorney's law firm) for refusing to answer questions about the U.S. business dealings of now-deposed Philippine President Ferdinand Marcos and his wife. The subcommittee overruled the witness' claims of attorney-client privilege on two grounds: that the privilege was not available as a matter of right and that, in any event, the claims would be spurious before a court.

The Foreign Affairs Committee, on Dec. 19, also found contempt, relying principally on the latter ground, but not rejecting the former. On Feb. 27, the full House voted to send the contempt citations to the U.S. attorney for prosecution.

As Reps. Dymally and Solomon rightly perceive, these proceedings have left large questions as to when the attorney-client privilege applies and when it does not.

Those who say the privilege is not available as a matter of right before Congress make three arguments, all seriously flawed.

First, they contend that the privilege applies only in an adversary context such as a trial, and that a congressional investigation is nonadversarial.

The privilege, however, is of little value if the client cannot be assured that it applies in all contexts, since otherwise the client will not know that what he tells his lawyer will remain secret. The Supreme Court has said that "an uncertain privilege . . . is little better than no privilege at all."

Moreover, a grand jury investigation is also an investigatory, nonadversarial proceeding, but, as the Supreme Court has recognized, the privilege indisputably applies in that setting.

Second, it is claimed that Congress, and the British Parliament as well, historically have viewed the privilege as discretionary. But history teaches an uncertain lesson because many committees -- for example, the Senate Watergate Committee -- have treated the privilege as one of right.

Third, the argument goes, a common law, nonconstitutional privilege cannot be allowed to defeat Congress' constitutional right to investigate.

The privilege, however, arguably has constitutional underpinnings in a variety of circumstances. For example, to force a lawyer to loose a client's confidences might impinge on the client's Fifth Amendment right against self-incrimination.

It is also problematic whether a constitutional power must always prevail over a common-law right. Grand juries undoubtedly have a constitutional right to investigate, but the attorney-client privilege is a legitimate barrier to grand jury probes.

While there is no definitive court opinion, a court likely would find that the attorney-client privilege is available as a matter of right before Congress, just as it is before courts and administrative agencies. But Congress itself should recognize that the privilege has socially useful goals and reach the same result. A statute may not be necessary, but congressional rules or resolutions validating the privilege would be appropriate and would obviate needless controversy.