Mayor Throws Support to Yaroslavsky : Election: The endorsement by Riordan, expected today, is seen as a key break in the 5th Council District campaign.

Providing what is being viewed as the most significant endorsement of the race, Mayor Richard Riordan is throwing his support behind Barbara Yaroslavsky in the race to fill the vacant 5th District City Council seat, sources said Monday.

The endorsement by the Republican mayor is expected to provide Yaroslavsky with a major boost in her efforts to win the seat left vacant when her husband, Zev Yaroslavsky, resigned to take a post on the County Board of Supervisors.

“I think it lends a lot of credibility to her race,” said political consultant Richard Lichtenstein. It also enhances her efforts to win over business owners and conservative voters in the San Fernando Valley, he said.

The endorsement is expected to come today during a news conference at the Los Angeles Free Clinic, where Barbara Yaroslavsky has been a long-time volunteer. Also attending will be City Controller Rick Tuttle and County Supervisor Zev Yaroslavsky, both of whom declined to comment on the event.

The 5th District includes a sizable portion of Van Nuys and runs from Sherman Oaks to Westwood.

Barbara Yaroslavsky is considered to be one of the top candidates for the post because of the name recognition she carries. That recognition and her husband’s powerful position are also expected to attract hefty campaign contributions, according to political consultants.

The election is set for April 11 and, if needed, a runoff will be held June 6.

Although the endorsement has been the subject of rumors for months, City Hall insiders have said that Riordan’s staff has urged him to stay out of the race. His aides fear that if he backs a losing candidate, he will be forced to work with a winner who may harbor animosity over the endorsement.

Still, the endorsement did not come as a surprise to several of the other candidates, some of whom noted Riordan’s close ties with Zev Yaroslavsky. Last year, Riordan endorsed Zev Yaroslavsky when he ran for the supervisorial seat.

The endorsement is expected to cause the greatest damage to the candidacy of Roberta Weintraub, a former school board member who endorsed Riordan for mayor and was, in turn, appointed by Riordan to the Library Commission.

Weintraub said she was hurt to hear about Riordan’s endorsement because she was a loyal supporter in 1993 when Riordan ran for mayor against Councilman Michael Woo.

“Yes, I’m very hurt,” she said. “For me, loyalty in politics is very important.”

Weintraub speculated that the mayor may have made the endorsement to return a favor to Zev Yaroslavsky.

“Maybe he owes him something big,” she said.

Lea Purwin D’Agostino, a deputy district attorney who is also considered a leading candidate for the council seat, said she was disappointed in the endorsement because she too supported Riordan in his mayoral bid.

But she added: “I promise I will not hold it against him after I’m elected.”