There’s going to be one definite runoff election next month — for public advocate.
The race for an office with a measly budget of $2.3 million was headed for an Oct. 1 runoff after City Councilwoman Letitia James won the five-way Democratic primary Tuesday night with less than 40 percent of the vote.
Under state election law, she now has to face the second-place finisher, state Sen. Daniel Squadron.
That means taxpayers will be picking up the tab, estimated at about $20 million — whether or not there’s a need for a runoff in the Democratic contest for mayor.
James, who represents the Fort Greene and Clinton Hill sections of Brooklyn, led Squadron, 36 to 33 percent, with 97 percent of election precincts reporting.
Reshma Saujani came in at 15 percent and Cathy Guerriero was at 13 percent, while Sidique Wai trailed with 3 percent.
Squadron — who represents Williamsburg and Greenpoint and who grabbed a key endorsement from The New York Times — outspent James by more than two to one, raising a total of $3.6 million to her $1.5 million.
James derided the lack of affordable housing and got the backing of the Working Families Party.
The Public Advocate’s Office will be left vacant with the departure of Bill de Blasio, who won the Democratic mayoral primary. The office, created in 1993, is meant to be a watchdog over the government but has also served as a springboard for higher office. The public advocate is first in line to replace the mayor in case of an emergency.
In 2010, Mayor Bloomberg blasted the office and called to have it abolished, saying it was “a total waste of everybody’s money.”
In other races, Upper West Side Councilwoman Gale Brewer grabbed the Democratic nomination in the Manhattan borough president’s race.
Brewer was outspent heavily by Julie Menin, a former chairperson of Community Board 1, who raised $1.8 million for the race. Despite her deep pockets, Menin ended up in fourth place, behind Brewer and Council members Jessica Lappin and Robert Jackson.
Also, former Councilwoman Melinda Katz won the Democratic nomination for Queens borough president over Astoria Councilman Peter Vallone.
Katz grabbed 44 percent to Vallone’s 33 percent.
Community organizer Everly Brown garnered 12 percent of the vote in the race for the Queens nomination while State Senator Tony Avella received 9 percent of the vote.
Incumbent Bronx Borough President Ruben Diaz cruised to an easy victory in the Democratic primary for his office with 84 percent of the vote.
Diaz, an entrenched politician, had been expected to trounce the political neophyte Mark Escoffery-Bey in that race.