The Cambridge City Council last night narrowly approved a controversial ordinance mandating residency for employees who earn more than $50,000.

The council approved the ordinance with a vote of five to four.

Councillors Sullivan, Jonathan S. Myers, Sheila T. Russell, Timothy J. Toomey and Anthony D. Galluccio supported the ordinance. All others voted against.

Last night's vote is not binding, as council members may vote again in a reconsideration. Myers, who worked with Toomey to rewrite the original ordinance, said last night the requirement is "about the employment and training of the city's residents."

Myers said the residency requirement is unlike the controversial residency requirement enacted by the city of Boston last year because it does not apply retroactively to workers but rather is intended to apply only to employees hired after January 1, 1996.

But Councillor Katherine Triantafillou, who had opposed the ordinance, condemned the amended version approved last night.

Saying the residency requirement was "anti-woman, anti-union, anti-veteran and fiscally irresponsible," Triantafillou said the regulation would discourage the city from hiring minority and better qualified candidates when a city resident was applying for the position.

Myers and Toomey defended the ordinance, saying language such as "when other employment factors are equal" was designed to ensure that the city continue to hire the best candidate for the job.

Myers downplayed the significance of the ordinance, saying residence will only be mandatory for the approximately 10 percent of city employees who earn more than $50,000.

But Triantafillou attacked the "Cambridge First" clause, which stipulates that applicants positions less than $50,000 will be given an "absolute priority" in the hiring process if other factors are equal.

She criticized the ordinance, saying it would be particularly hard on working wives and working mothers.

"Less than $50,000 penalizes the two-wage-earning family," she said. "Women don't have the kind of job leverage that men do."

Councillor Kathleen L. Born also said the council should consider the impact of the resolution on working, family women.

"It severely doesn't recognize the complexity of families that are struggling to raise a family on two incomes," she said, adding that many families find it necessary to live in a central location so that both spouses can commute.

Born also criticized the ordinance on legal grounds, citing a memo issued yesterday by City Solicitor Russell B. Higley which raised a number of legal questions about the ordinance.