The lawyers had repeatedly clashed with the woman in the dock, 40-year-old Beate Zschaepe, the surviving member of the alleged killer trio called the National Socialist Underground (NSU).
However, chief justice Manfred Goetzl averted a possible mistrial by ordering Zschaepe's public defenders to stick with the case, arguing they had not given sufficient grounds for quitting.
The NSU is blamed for the assassination-style gun murders of 10 people - eight men with Turkish roots, a Greek migrant and a German policewoman - between 2000 and 2007.
The gang's two male members, Uwe Mundlos and Uwe Boehnhardt, died in 2011 after a bank robbery in an apparent murder-suicide while hiding in their getaway vehicle, a rented camper van.
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Zschaepe, who had for years shared a house with the two men, has stayed silent since the start of her high-profile trial in May 2013, held under tight security in the southern city of Munich.
She has repeatedly clashed with the three court-appointed lawyers - Wolfgang Heer, Wolfgang Stahl and Anja Sturm - and tried unsuccessfully to fire them a year ago.
They must now keeping working, together with a fourth lawyer, Mathias Grasel, appointed several weeks ago.
Germany was shocked in 2011 to find that the bloody murder spree - long blamed by police and media on migrant crime gangs - was in fact committed by a far-right group with xenophobic motives.
The random discovery deeply embarrassed authorities, exposing police and domestic intelligence flaws and raising uncomfortable questions about how the cell went undetected for 13 years.