NEW YORK (AFP) – Days after coming second in New York’s Democratic mayoral primary, the city’s former financial controller Bill Thompson threw in the towel Monday and backed Bill de Blasio.

The move means that de Blasio, who won Tuesday’s primary with 40.3 percent, will face Republican Joe Lhota in November 5 elections for the powerful post.

Thompson, who got 26.2 percent in the primary, had refused to concede, saying not all ballots had been counted.

Even at a news conference Monday, he said “tens of thousands of votes” had yet to be tallied and that this was “a disgrace.”

Still, he said he was backing de Blasio, the city’s public advocate, because both wanted “to move our city forward.”

“I am proud to throw my full support behind him,” he said of De Blasio, the most left-leaning of the candidates.

Whoever wins in November will succeed the outgoing billionaire mayor, Michael Bloomberg, who has led the city for the past 12 years.

Thompson, who lost a previous bid to Bloomberg four years ago, had held out hope that de Blasio would drop below the 40 percent mark and force a run-off.

In the runup to the primary, de Blasio had run on an anti-Bloomberg platform, accusing the mayor of overseeing a widening gap between rich and poor.

De Blasio’s victory followed a bruising campaign overshadowed by the lurid sex scandal embroiling rival Anthony Weiner, who trailed in last.

Lhota, a 58-year-old former former Metropolitan Transit Authority president, scored a decisive victory to businessman John Catsimatidis in the Republican primary.

Bloomberg will leave his post on December 31.

New York is overwhelmingly Democratic, even though it has not elected a mayor from that party in 20 years. De Blasio appears well-placed to succeed him.