The head of a key City Council committee will disclose his opposition Wednesday to Mayor Bill de Blasio's effort to seek a prohibition on Central Park's horse-drawn carriages, according to people with knowledge of the planned announcement.

Councilman Rafael Espinal's opposition may upset de Blasio's plans to enact a ban legislatively because past carriage-related bills have originated in the Consumer Affairs Committee, which Espinal (D-Brooklyn) leads.

"He's a very important person because he's the chair," said Stephen Malone, spokesman for the Horse and Carriage Association. Malone said he and Demos Demopoulos -- president of Teamsters Local 553, which represents the carriage drivers -- would join Espinal at a City Hall news conference in which the councilman will oppose a ban.

Espinal, through a spokeswoman, declined to comment. He told Newsday in March that he was undecided but concerned about the economics of a ban, including "the loss of jobs and the loss of revenue for the city."

De Blasio and City Council ban supporters may be able to introduce a bill through a different committee.

De Blasio spokesman Phil Walzak said the administration is "considering a range of options" to take horses off the streets while protecting drivers' livelihoods.

De Blasio has long opposed the carriages as inhumane to horses. Earlier this month, he said poll numbers showing 61 percent of voters oppose a ban would change with "a full airing of the facts."