More than a half-century after he was locked in solitary confinement on Rikers Island, Victor Pate still avoids elevators.

“The enclosure, that small space when the doors close: It’s so reminiscent of going into that cell and the door closing on me,” Mr. Pate, 71, said at a City Hall rally supporting a bill that would ban solitary confinement in most cases in New York. “I’ve not gotten beyond that.”

To opponents of solitary confinement like Mr. Pate, who did time on a gun and car theft charges, prolonged isolation clearly qualifies as torture, causing long-lasting psychological damage and impeding rehabilitation. They call the bill, which the City Council is expected to pass on Wednesday, long overdue for the jail system, most notably Rikers Island, which is at risk of a federal takeover after years of dysfunction.

But Mayor Eric Adams and the union representing correction officers deny even the assertion that city jails use solitary confinement for discipline. Rather, they say what they call “restrictive housing” is used to isolate dangerous people and protect jail workers and other detainees.

Citing what they say are more than 6,500 assaults against correction officers over the past three years, they fiercely oppose the bill, arguing that the use of solitary confinement has decreased in recent years and so have “key indicators related to violence.”

“Instead of promoting a humane environment within our jails, the council’s bill would foster an environment of fear and instability,” said Kayla Mamelak, a spokeswoman for the mayor. “It would make it harder to protect people in custody, and the predominantly Black and brown workers charged with their safety, from violent individuals.”