Romanch’s Law followed the death of 18-year-old tourist Romanch Mahajan, who was thrown from a carriage earlier this year. Drivers argue the city failed to assess the ban’s economic impact.

Arthur Schwartz, a lawyer for the Transport Workers Union, said the proposed legal challenge would argue the ban violated the Constitution and state law.

“They can’t take away your property without due process,” he said.

The ban could affect about 150 active drivers, Manhattan stables and carriage medallions, some of which cost as much as $400,000.

Council Speaker Julie Menin said the legislation addressed longstanding concerns about animal welfare and public safety. Drivers say the city has failed to provide a clear plan for their livelihoods or the horses’ future.