By Edith Honan
NEW YORK (Reuters) - Bill de Blasio, a top New York City official and an unabashed liberal, clinched the Democratic mayoral nomination on Monday, setting the stage for a potentially divisive campaign against a Republican who served under tough-on-crime former mayor Rudolph Giuliani.
Bill Thompson, a former city comptroller who placed a distant second in last Tuesday's Democratic primary, conceded the race to de Blasio before all of the votes had been counted amid intense pressure from fellow Democrats to avert what could have been a bruising runoff.
Thompson's concession leaves de Blasio, the city's Public Advocate, facing Republican Joe Lhota, a former deputy mayor under Giuliani when the city's crime rate plummeted in the 1990s, and also onetime head of the city's mass-transit agency.
New Yorkers will decide in the November 5 election which one of them will succeed Michael Bloomberg, who is leaving after 12 years as Mayor of the most populous city in the United States with 8.3 million people.
De Blasio has campaigned to reverse Bloomberg's policies, describing New York as a "tale of two cities" - one rich and one poor. Lhota contends de Blasio is trying to split New Yorkers along class lines over policing and finances.
"Over the next two months voters will see a stark contrast between myself and Mr. De Blasio," Lhota said in a statement on Monday. "Dividing our city, increasing job-killing taxes and handcuffing our police is not the direction we need to take our city."
De Blasio needed 40 percent of the primary vote to avoid a runoff and won roughly that number compared with about 26 percent for Thompson. Thompson had earlier vowed to stay in the race until the counting of ballots of absentee voters and military personnel had been completed this week.
"There is nothing more beautiful than Democratic unity, and thank you for it," said de Blasio, as he stood with Thompson, New York Governor Andrew Cuomo and an array of other leading Democrats on the steps of City Hall.
De Blasio, who worked in the Clinton White House and later was a New York City councilman, has built his campaign around addressing income inequality and called for higher taxes on the rich to pay for expanded pre-kindergarten programs. He has been a fierce critic of the police tactic of stop and frisk, which critics say targets young black and Latino men.
Lhota, who describes himself as a fiscal conservative but a liberal on social issues such as same-sex marriage, has said he wants to win over moderates in the heavily Democratic city. Registered Democrats outnumber Republicans by six to one.
Lhota has been largely supportive of Bloomberg's anti-crime tactics, including the tactic of stop and frisk. He too has said he would work to expand access to pre-kindergarten programs -- but not by raising taxes -- and to affordable housing.
(Additional reporting by Ellen Wulfhorst; Editing by Lisa Von Ahn and Grant McCool)