The Supreme Judicial Court is considering whether a judge can choose the lawyers who serve in his drug court, a criminal justice alternative to jail for people addicted to drugs that has spread quickly across Massachusetts and the rest of the country in recent decades.

Lowell District Court Judge Thomas Brennan removed a public defender from the drug court last year after she challenged the way he runs the session, a voluntary program meant to keep people arrested on drug-related offenses out of jail if they accept mandated treatment and court supervision.

The Committee for Public Counsel Services, which oversees the state’s roughly 500 public defenders, fought the decision, arguing Brennan usurped the agency’s independent right to appoint counsel for poor defendants. The lawyer, Lisa Newman-Polk, had been appointed by CPCS to Lowell’s drug court team, a group that also includes a probation officer, treatment providers, and a prosecutor who work together to find treatment for an offender.

But tensions erupted between Brennan and Newman-Polk during a team meeting in September of 2015 when she asked that one of her clients who had been incarcerated for a probation violation be released from jail and sent to a sober house. Newman-Polk, who has a background in social work, had expressed concern that the court was incarcerating too many participants for relapsing on drugs or alcohol, according to court documents.

Brennan called her a “know-it-all’’ and said she was unwilling to listen to other members of the team, according to court documents. He dismissed her from the team a week after the meeting and refused to let her represent clients with probation violations. He later announced he would also bar CPCS lawyers from representing participants who did not have probation violations.

A Globe Spotlight story Sunday described how the Lowell drug court has sent probationers with mental illness to jail when they relapse.

The clash between Brennan and CPCS led to arguments Wednesday morning before the state’s highest court, where a lawyer for Brennan argued that the SJC should give the judge broad discretion to decide who serves on the drug court team and allow him to show preference for which lawyers are appointed to represent participants during court hearings.

But attorney Paul R. Rudof, arguing for CPCS, said asking for the ability to appoint “cooperative’’ attorneys is “deeply troubling.’’

“It really undermines the right to counsel for poor people in drug court and invites ethically perilous behavior by both judges and defense attorneys,’’ Rudof said.

Justice David A. Lowy asked Rudof if drug court participants shouldn’t expect their lawyers to collaborate more with prosecutors and judges than they do in a traditional court setting, where the process is more adversarial.

“I don’t think there is any understanding that you’re going to get a lawyer who . . . may advocate for you to go to jail,’’ Rudof replied.

Joseph Ditkoff, a special assistant attorney general representing Brennan, said the judge has acknowledged he made a mistake when he refused to let Newman-Polk continue representing clients without giving her a chance to be heard on the matter.

But, in a brief to the court, he said the judge should get to pick defense attorneys who staff the special session, pointing to research that shows drug courts are most successful when team members cooperate.

“The judge must choose dedicated members able to attend regularly, with a collaborative attitude and the ability to work well with the other team members,’’ Ditkoff wrote.

Some of the justices appeared troubled by the notion that a judge could be allowed to dismiss someone who does not agree with the rest of the team.

“You’re saying . . . that we can tell judges, ‘You can handpick the attorney?’ ’’ Chief Justice Ralph D. Gants asked. The SJC can let a judge tell a public defender, “ ‘If you don’t vote this way, we’re going to fire you?’ ’’

Ditkoff said yes. But he cautioned he was not proposing a lawyer in the drug court should fear repercussions for standing up for a client.

“The role of [defense attorney] is to zealously advocate for all the drug court participants,’’ he said. “If you feel that you should zealously defend your client but reject the drug court model, then you shouldn’t be on the drug court team.’’

Lowy said those two goals may conflict if a lawyer feels the court is punishing a client for a probation violation.

“Ultimately the lawyer in there has to do what he or she thinks is right by the client,’’ Lowy said.

Maria Cramer can be reached at mcramer@globe.com.