A federal appeals court on Friday refused to toss out court rulings finding that New York City carried out its police stop-and-frisk policy in a discriminatory manner. The refusal ended what was likely the city's last chance to nullify the decisions before the arrival of a new mayor who has criticised the tactic.

A three-judge panel of the 2nd US circuit court of appeals issued a five-page order, saying the city could make its arguments to toss out the rulings when its appeal of the decisions of US district judge Shira Scheindlin is heard next year. Last month, the same appeals panel suspended the effects of Scheindlin's rulings and removed her from the case, saying she misapplied a related ruling that allowed her to take the stop-and-frisk case and made comments to the media during a trial that called her impartiality into question.

The city had argued that the panel's decision to remove Scheindlin meant it should also nullify her rulings. But the appeals judges rejected that without comment, while saying the city could ask the appeals court to return the case to a newly appointed judge in the lower court "for the purpose of exploring a resolution”.

The appeals court also rejected claims by a lawyer for Scheindlin that it had not seen enough of the court record before removing her from the case, saying it had.

Scheindlin ruled in August that police officers sometimes carried out stop-and-frisk unconstitutionally by discriminating against minorities. The appeals court's action appears to spoil the city's bid to get Scheindlin's rulings tossed before the Democrat Bill De Blasio, who is sympathetic to her viewpoint, takes office as mayor in January.

The stop-and-frisk program lets police stop someone when there is a reasonable suspicion that a crime is about to occur or has occurred — a standard lower than the probable cause needed to justify an arrest. Only about 10% of the stops result in arrests or summonses, and weapons are found about 2% of the time.

De Blasio has repeatedly stated that he would order the city to drop its appeal. He had filed papers with the district court and the 2nd circuit opposing the city's effort to stay the effect of the rulings. De Blasio could also settle with those urging reforms, eliminating federal oversight.

The city's top lawyer, Michael A Cardozo, said the city was "moving ahead full speed with its appeal, and we maintain that the city's police force has acted lawfully in its application of stop, question and frisk".

The Center for Constitutional Rights, which represents plaintiffs in the stop-and-frisk case, said in a statement that it hopes De Blasio drops the city's "desperate appeal".

"He has an extraordinary opportunity to use the expertise of a court monitor and policing experts to end discriminatory policing," it said.