MONTGOMERY, Ala. — Three days after a plea for forgiveness, the release of a damning investigative report and a swirl of legal drama, the political future of Gov. Robert Bentley of Alabama faces a new test on Monday as state lawmakers begin to hear evidence that could lead to his impeachment.

Mr. Bentley, a Republican in his second term, is confronting a crush of allegations after his March 2016 acknowledgment of improper communications with his senior political adviser, Rebekah Caldwell Mason. In a report released on Friday, a special counsel to the Judiciary Committee in the Alabama House of Representatives said Mr. Bentley had “encouraged an atmosphere of intimidation” and demanded that state officials help him cover up an “inappropriate relationship.”

Mr. Bentley, 74, who has said he did not break the law, tried to block Monday’s hearing, and won a reprieve in a Montgomery County court. But the Alabama Supreme Court ruled on Saturday that, at least for now, the proceedings could begin, clearing the way for the special counsel, Jack Sharman, to explain his findings in a public setting. Mr. Bentley’s lawyers are scheduled to mount a defense on Tuesday, and the full House could vote on the governor’s fate early next month.

“I do not plan to resign,” Mr. Bentley said on Friday, repeating the position he has maintained for more than a year. “I have done nothing illegal.”

But as the impeachment hearings neared, Montgomery bubbled with speculation that Mr. Bentley was planning to resign soon. His spokeswoman, Yasamie August, said in an email Monday morning that, “The governor is not personally involved in any negotiations.”

The turmoil has enthralled and unsettled people across Alabama, where, less than seven years ago, Mr. Bentley mounted the upstart campaign that catapulted him from obscure legislator to governor. Now Mr. Bentley has become extraordinarily isolated: Last week, the Legislature’s ranking Republicans called for his resignation, and the State Ethics Commission found probable cause to ask a district attorney to consider prosecuting the governor.

The Ethics Commission’s decision only added to the legal troubles of Mr. Bentley, whose office has faced months of scrutiny by other government agencies, including the F.B.I. and the Alabama attorney general’s office.

But the developments of recent days transformed a slow-moving scandal into a fast-paced and sensational clash centered on the political power and marital fidelity of a former Baptist deacon.

Mr. Sharman’s 131-page report offered a startling narrative that depicted Mr. Bentley, who offered only limited cooperation to legislative investigators, as craven, desperate and bedeviled by “increasing obsession and paranoia.”

Mr. Bentley, the report concluded, was particularly anxious about recordings that his wife at the time, Dianne Bentley, made of conversations between the governor and Ms. Mason, who did not respond to an email on Sunday. In one such recording, the governor described embracing Ms. Mason and placing his hands on her breasts.

In his report, Mr. Sharman also described how Mr. Bentley tried to use a member of his security detail to break up with Ms. Mason on his behalf and how the governor demanded that Ms. Mason be allowed to travel in official vehicles even after she left the state’s payroll. The report also alleged that Mr. Bentley’s critics had been subjected to coercion, including threatening messages and the specter of criminal prosecution.

In one instance, the governor was accused of threatening to retaliate against an aide to Ms. Bentley if the employee disclosed Mr. Bentley’s relationship with Ms. Mason.

“You will never work in the state of Alabama again if you tell anyone about this,” the aide, Heather Hannah, quoted Mr. Bentley as saying during a confrontation in the kitchen of the governor’s mansion.

Lawyers for Mr. Bentley contend that his behavior does not warrant impeachment — a rare sanction for American governors — and have raised due process concerns. Standing before reporters outside the State Capitol here on Friday morning, Mr. Bentley also complained about what was unfolding.

“The people of this state have never asked to be told of or shown the intimate and embarrassing details of my personal life and my personal struggles,” the governor said. “Those who are taking pleasure in humiliating and in shaming me, shaming my family, shaming my friends, well, I really don’t understand why they want to do that.”

Then he offered speculation and a plea.

“It may be out of vengeance,” said Mr. Bentley, whose former wife filed for divorce in August 2015. “It may be out of jealousy. It may be out of anger. It may be out of personal political benefit, I don’t know. But I would ask them to please stop now. Our state doesn’t need this anymore.”

Hours later, Mr. Sharman’s report became public. On Sunday night, the Alabama Republican Party said its steering committee had decided to call for Mr. Bentley’s resignation.