While Pedro Espada fends off multiple law suits, Desiree Pilgrim-Hunter, the Fordham Hill activist taking Espada on for the 33rd Senate District seat, is gaining momentum, picking up a big labor endorsement and scheduling fund-raisers with deep-pocketed Democratic donors.

Last week, the Retail, Wholesale and Department Store Union (RWDSU), endorsed Pilgrim-Hunter, her first major institutional endorsement. The RWDSU partnered with Pilgrim-Hunter and the Northwest Bronx Community and Clergy Coalition in helping stop the city’s plan to turn the Kingsbridge Armory into a shopping mall.

A couple of weeks ago, Pilgrim-Hunter met with Israel Rivera, the secretary-treasurer of the TWU Local 100, according to a source close to her campaign.

Even considering Pilgrim-Hunter’s recent good fortune, she still must make up a mountainous fund-raising deficit if she hopes to beat Espada, who has raised $304,450, according to his latest state campaign finance filings.

She is hoping to raise $100,000 at a May 26 fund-raiser hosted by Cathy and Marc Lasyr, two big-time Democratic donors, at their Upper Eastside home, according to the Daily News.

Pilgrim-Hunter is looking to make up a mountainous fund-raising deficit. According to her actblue.com web page, she’s raised $6,183 so far. (That’s only online contributions, according to Yorman Nunez, a campaign adviser. That doesn’t include how much Pilgrim-Hunter has raised through house parties and other events, but Nunez wouldn’t disclose that amount.)