Former state Sen. Dianne Wilkerson, a Roxbury Democrat who pleaded guilty earlier this year to federal extortion charges, is scheduled to be sentenced on Dec. 22. Prosecutors have asked for Judge Douglas Woodlock to sentence her to four years in jail, while her defense attorneys say she should receive considerably less, given her history of helping the needy.

The two sides will spar over whether Azid Mohammed, a local contractor who allegedly gave money to Wilkerson, should be factored into the federal judge’s sentencing. Wilkerson’s attorneys say he volunteered to provide the money as a gift, while prosecutors say the money was solicited and illegally provided.

Mohammed is expected to take the stand that day, to be questioned by both Wilkerson’s attorneys and prosecutors. John McNeil, the lead prosecutor, raised the possibility of Wilkerson also taking the stand.

In a court filing, her defense attorneys wrote that Mohammed met Wilkerson through a minister while he was looking for support for developing a Roxbury parcel.

“The relationship become much more than that, as he became very close to defendant and her family,” they wrote. “Starting in 2002, on a number of occasions, he offered her money to assist her with her well publicized financial problems. The money was volunteered and not requested, and presented by him as made out of friendship and sympathy. Neither she nor he ever said anything to tie this assistance to her support for his project (and he testified in the grand jury that she said there were no strings attached).”

The defense attorneys sought to poke holes in his grand jury testimony, of which they released only a partial transcript. Mohammed had said he paid Wilkerson $10,000 because she asked and because he felt he needed to do so in order to maintain her support for his project “although he added that she always said that the two were not connected and he could not expect anything,” the attorneys wrote.

Her attorneys also said Mohammed claimed to authorities that he was not friends with Wilkerson, despite at one time sharing office space with her sons and driving a van out to Springfield in 2007 in order to transport people to a service for Wilkerson’s father, who had passed away.

 “During the course of the government investigation, Mohammed made extreme claims concerning the willingness of certain elected officials to take bribes (which he later admitted were false), and then agreed to act as the front man in the agents’ plan to offer them money,” her attorneys wrote. “Later, after defendant was arrested, he was interviewed. At first he lied, and denied ever having given the defendant money. Then he was confronted by his checks to her, and informed of his own exposure to prosecution. As he later told defendant’s son, ‘[t]hey got me by the balls.’”

But prosecutors, in their response, referred to Mohammed as “A.M.” and stated he stopped paying Wilkerson when his development project went dormant; gave her money when he learned there was a competitor for the Roxbury parcel; and hid his payments to Wilkerson from his business partner. McNeil told the judge he doesn’t expect Mohammed to change his grand jury testimony while on the stand at Wilkerson’s sentencing.

Separately, Woodlock, the judge, said he could factor in the presence of Wilkerson’s granddaughter during an August 2007 payoff. The payoff occurred at the Fill-A-Buster restaurant on Beacon Hill, while the granddaughter was away from the table.

“I raise it because it was rather striking to me,” Woodlock said, adding that it “touches on family responsibilities.”