PORTLAND – Mark Strong Sr., one of the key defendants in the high-profile Kennebunk prostitution case, is in closed-door negotiations Friday morning with his lawyers, prosecutors and a judge about a possible plea deal.

If the plea talks fall through, Strong, 57, of Thomaston, is scheduled to stand trial Tuesday in York County Superior Court in Alfred to face 59 misdemeanor counts accusing him of conspiring with Alexis Wright to run a meticulously documented prostitution business from her Zumba studio in Kennebunk.

Prosecutors have released a preliminary witness list with 57 names on it, including police, phone and bank experts, Kennebunk locals and 18 men who have pleaded guilty to engaging in prostitution in connection with Wright.

The trial, if it happens, is scheduled to last about three weeks.

Strong is scheduled to appear for another hearing sometime Friday in the Cumberland County courthouse in Portland on a motion filed by his lawyer, Daniel Lilley, seeking to withdraw from the case on grounds that Strong doesn’t have enough money to pay for his legal defense at the trial or to hire expert witnesses he would need to adequately defend himself.

The plea deal talks are being held with Justice Thomas Humphrey.

The hearing on Lilley’s motion to withdraw from the case will be held before Justice Nancy Mills, who would be presiding at the trial.

Lilley stepped out of plea talks at 10:30 a.m. to say the hearing on his motion to withdraw from the case may not be heard until the afternoon.

“This is taking longer than expected,” Lilley said of the plea negotiations.

Lilley said he was not permitted to say anything more and returned to the plea negotiations behind closed doors..