Following tradition, the New York City candidates seeking to replace Mayor Michael Bloomberg ceased campaigning on Sept. 11, the 12th anniversary of the terrorist attacks.

A day later, they are expected to break their silences — and then some.

Public Advocate Bill de Blasio, who emerged from Tuesday’s primary election as the front-runner, was slated to receive the support Thursday of unions that had previously backed City Council Speaker Christine Quinn, who finished a distant third. Late Wednesday night, the building service workers’ union, SEIU Local 32 BJ, which had previously backed Quinn, endorsed de Blasio.

Former comptroller Bill Thompson, the second-place finisher in the Democratic mayoral primary, did not release a public schedule. But Thompson vowed Tuesday night to stay in the race as the city’s Board of Election recounts the votes.

De Blasio garnered 40.3 percent of the vote with 99 percent of precincts reporting Tuesday. But whether he will be the Democratic nominee in the November election remains to be seen.

To avoid an Oct. 1 runoff against Thompson — who received 26 percent of the vote — de Blasio needs 40 percent to become the outright nominee.

About 645,000 votes were cast in Tuesday’s election — and on Thursday, the Board of Elections will bring back voting machines from local precincts to borough headquarters ahead of Friday’s recount. On Monday, officials will add to the tally at least another 16,000 outstanding absentee and special ballots.

Republican Joe Lhota, who handedly won his party’s nomination, was scheduled Thursday to make two TV appearances, be a guest on a radio show, address a town hall in Manhattan and pay his respects to the gravesite of a famous rabbi ahead of the Yom Kippur holiday.

Lhota, a one-time deputy mayor to Rudolph Giuliani and former head of the Metropolitan Transit Authority, won the Republican nomination outright.

The race to succeed Bloomberg is shaping up as a referendum on the 12-year legacy of the billionaire who guided the nation’s biggest city through the aftermath of 9/11 and the meltdown on Wall Street.

De Blasio has been the most vocally anti-Bloomberg of the major candidates. But Lhota won his party’s nomination after tying himself closely to many of Bloomberg’s policies.

Bloomberg, a Republican-turned-independent is leaving office after three terms.

Lhota, whose party is outnumbered by Democrats 6-to-1 in the city, is trying to project an aura of stability to independents, moderates and business leaders wary of de Blasio’s fiery rhetoric.

Lhota has said repeatedly that he will seek Bloomberg’s endorsement. Bloomberg did not publicly back anyone during the primary campaign.

(AP)