The federal judge who last year mandated broader judicial oversight over the FDNY “abandoned a neutral role” while presiding over the case and injected personal, “extrajudicial beliefs,” city lawyers wrote in appeal papers.

The city argued that federal Judge Nicholas Garaufis became both a “witness and advocate” during the case, before ruling that a court-appointed monitor should supervise the hiring and promotion of minorities at the FDNY where 93 percent of firefighters are white.