New York Mayor Bill de Blasio was booed Wednesday night at the famous Rockefeller Center Christmas Tree lighting ceremony, as he flipped the switch on live TV.

The liberal mayor was outside 30 Rock as part of the annual event televised on NBC. But, despite winning re-election comfortably last year, de Blasio was booed when announced by the hosts, moments before the tree lit up.

Hizzoner smiled and waved, but the boos could easily be picked up on the TV mics.

De Blasio has been booed in a number of public appearances, including at a Columbus Day parade last year over his ordering of a task force to consider the removal of monuments of historical figures -- including Christopher Columbus.

But de Blasio has not backed down. This month, he cited his "socialistic impulse" in describing an ideal world where New York City government has control over all land and buildings in his city.

DE BLASIO, CITING 'SOCIALISTIC IMPULSE,' WANTS MORE GOVERNMENT CONTROL OF NYC PROPERTY

“I think people all over this city, of every background, would like to have the city government be able to determine which building goes where, how high it will be, who gets to live in it, what the rent will be,” de Blasio said in a wide-ranging interview with New York Magazine. “I think there’s a socialistic impulse, which I hear every day, in every kind of community that they would like things to be planned in accordance to their needs.”