Willie Rivera, a staffer for Democratic state Sen. Michael Rubio, has thrown his hat in for the open Ward 1 Bakersfield City Council seat.

Rivera plans to hold a press conference Monday at 11 a.m. at Bakersfield City Hall North, 1600 Truxtun Ave., to announce his candidacy, according to an announcement from Candi Easter, chair of the Kern County Democratic Party.

Rivera didn't return calls Wednesday.

The Ward 1 seat opened up when Rudy Salas, also a former staffer for a state legislator, left to take up the 32nd Assembly District seat he won last November.

In January, the city council voted to hold a special election for the seat in response to Ward 1 residents gathering thousands of signatures asking for a special election. They said they felt compelled to hold an election seeing the huge support for one.

The election is slated for June 4.

Rivera and Marvin Dean, who ran for the Ward 1 seat against Salas in 2010, both have filed forms announcing their intention to run for the opening, said City Clerk Roberta Gafford. The period to file nomination papers, which means actually filing to run for the seat, starts Monday and runs to March 8, Gafford said.

Potential candidates then have to gather valid signatures from 20 registered voters in the ward to file to be a candidate.