's latest lawyer, Sorrell Trope, filed a request Wednesday to withdraw from the singer's custody case, court documents show.
"There has been a breakdown in communications between (Spears) and Trope & Trope (law firm) making further representation of her interests impossible," says the document.
Trope gave no further details. But he told PEOPLE the ultimate decision to quit isn't up to him.
"A lawyer cannot simply withdraw from a case," he says. "We will ask the court to relieve us." A hearing is set for Feb. 4.
That will be followed by a hearing for Spears and Kevin Federline
in the custody case on Feb. 19.
Trope was Spears's third lawyer in her ongoing battle with her ex-husband.
Her first attorney, Laura Wasser, resigned from her case
in September shortly after Spears's divorce from Federline was finalized.
Spears then hired the firm Freid & Goldsman, but their relationship ended within days.
Trope faced an uphill legal battle in the Spears case. Shortly after his firm took over, the singer temporarily lost custody
of her sons, Preston, 2, and Jayden, 1.
While she did regain her visitation rights, Trope's tenure has been fraught
with setbacks, including Spears missing numerous drug-testing calls, her
skipping of a deposition due to an alleged illness, and her questionable
The request to withdraw was first reported by TMZ.com.