An appeals-court panel on Tuesday unanimously ordered the de Blasio administration to release communications between the Mayor’s Office and a consultant that City Hall has been trying to hide for three years.

The ruling upholds a March 2017 State Supreme Court decision dismissing City Hall’s claim that communications with BerlinRosen are confidential.

“Based on the substantial body of law . . . respondents had no reasonable basis to withhold the documents,” wrote Justice Anil Singh.

The city must pay the legal fees of plaintiffs The Post and NY1, the court said.

Law Department officials wouldn’t say if they’ll appeal, and Mayor Bill de Blasio dodged questions about the case at an event in Newark.

BerlinRosen declined to comment.