A full 20 months into the mayor's first term, 47 percent of voters said he does not deserve reelection in 2017, while 41 percent said he does. There is a wide racial disparity in the numbers.
Black and Hispanic voters, who have overwhelmingly supported the mayor, remain strong supporters.
Black voters, by a margin of 58 percent to 33 percent, believe that de Blasio deserves to be reelected. Hispanic voters back a second de Blasio term by 49 percent to 40 percent. White voters say that de Blasio does not deserve reelection by a margin of 61 percent to 29 percent.
“The mayor has yet to close the book on the tale of two cities, written on Election Day 2013. Black voters still approve of de Blasio by a lot; white voters don't," Quinnipiac University Poll Assistant Director Maurice Carroll said in a statement.
De Blasio also received his worst overall rating ever.
The poll found that 44 percent of voters approve of the job de Blasio is doing versus 44 percent who disapprove. A May 12 poll found that the mayor had the same approval rating, but a 40 percent disapproval rating.
“The election calendar keeps getting shorter. So even though it's two years away ... de Blasio has to be concerned that his re-election numbers are narrowly negative,” Carroll said.
De Blasio spokesman Wiley Norvell dismissed the poll.
“This is a mayor who focuses on the fundamentals New Yorkers care about, not political chatter," said Norvell.
"What matters are results: crime is down 6 percent from last year’s record lows, more affordable housing is being built than at any time in the past 40 years and the city has added more than 150,000 jobs since the mayor took office."
Cuomo received a 58 to 36 percent approval rating and Stringer's approval rating was 54 percent to 21 percent.
De Blasio has faced off against Cuomo, saying the governor sabotaged the city's Albany legislative agenda. The poll found that 41 percent of voters agreed with that statement but 39 percent said the mayor just didn't work hard enough.
The pair continue to have public disagreements on policy that are unusual for two leading officials in the same party.
Stringer is often mentioned as a future mayoral candidate.
"Stringer is a serious guy with a serious job who raises serious issues. He is clearly positioned to run for something larger but he doesn't have to deal with the spotlight the same way the mayor does," said Evan Thies, a political consultant and president of Brooklyn Strategies.
"His opponents have found soft spots in the mayor's performance and agenda and it has affected his numbers," Thies said.
City Hall officials compared the fight with Uber to de Blasio's battle with the charter school lobby last year that caused a dip in his approval ratings before they rebounded.
Working in de Blasio's favor is his continued strong support among blacks and Hispanics.
"As long as a majority of Democrats support the mayor, which they do according to this poll, he's still a very hard guy to beat in a primary," Thies said.