SAN FRANCISCO — In three decades of practicing law, Morrison & Foerster partner William Stern says he’s never had to ask a judge to find a new lawyer for a client. But this week, Stern’s 30-year streak ended.

Pointing to unpaid fees and a “fundamental disagreement” over litigation strategy, Stern’s team filed a motion Monday to withdraw as defense counsel for Bromley Tea Company in one of the Northern District’s many food labeling suits.