Tobacco industry lawyers have become the focus of a bitter dispute concerning their role in lobbying New Jersey state legislators for a law that seriously weakened a smoker's product-liability case.

A key issue is the role that may have been played by the lawyers, who are the defense counsel in the case, in drafting the New Jersey Product Liability Act of 1987 to make it apply to a suit filed in 1983. Judge H. Lee Sarokin has set today for a hearing in U.S. District Court in Newark.

The law incorporates a restrictive legal doctrine concerning torts, or wrongful acts, under which a product such as a cigarette can't be deemed defective because its alleged risks have long been part of the common knowledge of consumers.

Its passage severely weakened the case of Antonio Cipollone, whose wife, Rose, died of lung cancer in 1984, when she was 58. She had smoked heavily since she was 16. The defendants are Liggett Group Inc., Philip Morris Inc. and P. Lorillard Inc. One of Cipollone's claims -- that the risks of cigarettes outweigh their utility and make them "an unreasonably unsafe" and therefore "defective" product -- is affected by the New Jersey law.

Both defense and plaintiffs' lawyers agree that the new law bars a smoker from using that risk/utility claim in a lawsuit filed on or after the date of enactment -- last July 22. What they disagree about is whether the legislature intended the law to knock out risk/utility claims in cases, such as Cipollone's, that were pending in the state's courts before that date.

The text of the law provides no answer while appearing at first blush to protect risk/utility claims in pending cases. That's because of a provision saying the statute "shall apply only to actions filed on or after the date of enactment."

But the Assembly Insurance Committee, without holding hearings, issued a statement declaring the legislature's intent was that the law apply retroactively. Judge Sarokin subsequently ruled that the law did indeed strike down Cipollone's risk/utility claim, and granted a defense motion for a partial judgment without trial. Plaintiff's attorney Marc Z. Edell said at the time that the ruling "substantially undermines our case."

In papers filed in U.S. District Court in Newark, Cynthia A. Walters, an associate of Edell, raised the possibility of "an illegal and unethical attempt by lobbyists to place words in the legislators' mouths." Walter also said in an affidavit that "it is believed" an industry lawyer drafted the insurance committee statement. She supplied no documentation for that belief.

The companies haven't denied that an industry lawyer played such a role, while emphasizing what they see as an attack on the rights guaranteed to them by the New Jersey and U.S. constitutions.

Both sides cite an affidavit submitted by defense lawyer John P. Sheridan Jr. in an effort to quash a plaintiff's subpoena in another smoker's case to testify about his role as "a legislative advocate." He is a member of Riker, Danzig, Scherer, Hyland & Perretti of Morristown, N.J. The firm represents R.J. Reynolds Tobacco Co. and has had what Sheridan called "a joint defense relationship with law firms representing other tobacco companies."

Sheridan said in the affidavit that he and his firm were retained by Covington & Burling, a leading Washington law firm, "on behalf of a group of tobacco companies to provide legal advice and representation in connection with potential legislation in New Jersey concerning product liability law and tort reform."

He said he registered under a New Jersey lobbyist-disclosure law "as a legislative agent for Covington & Burling and disclosed that my fees were ultimately being paid by members of the tobacco industry." At all pertinent times, he said, Philip Morris and Reynolds were among his clients.

The judge has granted a motion by Edell and Walters for reargument on his October ruling. On Dec. 28, two weeks after the hearing, he ruled that the origin of the Assembly committee statement was of "critical" importance because of "allegations of impropriety in {its} creation."

He directed the cigarette industry to file an affidavit stating the no representative of the industry helped prepare the statement, or to specify those persons who did play such a role. He further ordered that theplaintiff be allowed to take depositions of those persons before Jan. 6, 1988.

No such affidavit has been provided. Instead, industry law firms filed papers to block the pretrial discovery ordered by Sarokin. The law firms, including Washington's Arnold & Porter, which represents Philip Morris, also charged that allowing Walters and Edell to take depositions from defense lawyers, and compelling them to produce "confidential documents," would be "an unjustifiable invasion" of First Amendment rights. The plaintiff's lawyers have cited no precedent "which has relied on lobbying activity or influence to discredit legislative intent," they argued.

In a reply, Walters accused the defendants of a "failure to comply with" the judge's order and said the failure "should be construed as an admission of their questionable activities in the legislative process and in the preparation of" the Assembly committee statement.

The tensions created by the dispute have been increased by a related unusual development: plaintiffs' lawyers have subpoenaed eight of the defense lawyers as potential trial witnesses. Jury selection is set to begin Tuesday.