Bill de Blasio’s first interview as a presidential candidate was marred on Thursday by protesters chanting “Liar!” and “Can’t run the city! Can’t run the country!” throughout the live segment.

The mayor appeared on “Good Morning America” to plug his ambitions for the White House — but was greeted by some 60 demonstrators outside the Times Square studio.

As the chants cut through George Stephanopoulos’ questions, de Blasio downplayed the debacle as “a little serenade.”

But Stephanopoulos reminded the mayor of a recent poll that found 76 percent of New Yorkers urged him not to run.

“So what should the rest of the country think?” Stephanopoulos asked.

“The poll that actually matters is the election,” said de Blasio, flanked by his wife, Chirlane McCray. “It’s not where you start, it’s where you end.”

He also gave President Trump a new nickname — “Con Don.”

“He’s conned us into thinking that he’s on the side of working people when he’s really on the side of the 1 percent,” the termed-out pol said.

McCray, calling herself de Blasio’s “top adviser,” touted her crusade for mental health, even though her ThriveNYC initiative has come under attack for being inefficient and ineffective.

Additional reporting by Elizabeth Rosner