A federal judge yesterday refused to halt enforcement of the 1989 Ethics Reform Act, which bars federal employees from receiving outside income from speaking or writing.

U.S. District Judge Thomas Penfield Jackson declined to prevent the law from going into effect Jan. 1, saying the employees failed to show they would be "irreparably damaged" by the law.

But Jackson's ruling left alive the volatile issue of how much federal employees' outside activities can be limited without infringing their First Amendment rights. The plaintiffs -- the American Federation of Government Employees (AFGE), the National Treasury Employees Union (NTEU) and 10 employees represented by the American Civil Liberties Union -- said they would file an emergency appeal to the D.C. Circuit Court of Appeals.

The ban on honoraria, a byproduct of congressional actions to limit outside income received by members of Congress, applies to all federal employees except senators.

Jackson said he was denying the plaintiffs' motion for a temporary restraining order only on procedural grounds. He said the wording of the law "couldn't be broader," and that the case presented "a substantial legal issue."

"I am disappointed that I will not have the opportunity to give the thought these cases deserve," Jackson told attorneys for both sides. "I wish you Godspeed to the fifth floor" of the federal court house -- where the D.C. Circuit is located.

The 45-minute hearing came as an eleventh-hour coda to a fractious congressional debate last year over pay raises for members of Congress. As part of a package of bills passed by Congress on Nov. 16, 1989, members of the House got a pay raise that totaled 33 percent by Jan. 1, 1991. In exchange, representatives gave up all outside income from public appearances, speaking engagements or writing. The House ban was triggered by several financial scandals of members, including one involving honoraria received by former speaker Jim Wright (D-Tex.), who resigned.

But the honoraria ban raised immediate protests from lower-level civil service employees who depend on outside writing or lecturing to supplement their incomes.

The issue simmered all year as federal employees' unions waited for a legal interpretation from the Office of Government Ethics, which came only last month. It refined some definitions in the law, but left intact its general prohibition on all federal employees. At the same time, some federal employees' groups pressed for legislation exempting them from the ban. Those efforts died in committee in early fall.

Lawyers for AFGE, NTEU and the ACLU filed separate lawsuits challenging the law on First Amendment grounds. Those lawsuits were consolidated for the purposes of yesterday's hearing.

Lawyers for the employees argued that the ban infringes on the First Amendment rights of employees because it hinders them from pursuing secondary careers in areas unrelated to their work. Affidavits filed by the plaintiffs included statements from employees who are experts in topics as diverse as dance or 19th-century Russian history.

"We can work for McDonalds, we can clean johns" to get outside income, said one of the employees at yesterday's hearing, Judith Hannah, a researcher for the Department of Education. "We can do anything else for money. Why not writing? Why are people being penalized for the expression of ideas?"

But Justice Department attorney Jeffrey S. Gutman told Jackson the ban doesn't hinder federal employees from speaking or writing in any way.

"It's only the payment of speech, not the speech itself, which is prohibited," Gutman said.