An Amsterdam court on Friday ordered that three judges hearing an appeal brought by far-right Dutch MP Geert Wilders must step down, in a victory for the firebrand politician.
Three new judges will now have to be appointed to hear the appeal, brought by Wilders against his 2016 conviction for discrimination.
Wilders hailed the ruling as "Great!" on Twitter adding the court had "rightly found that the process was unfair and biased."
The decision by the special court comes a day after Wilders slammed his trial as a "witch-hunt" and clashed with the judges on the opening day of his appeal.
He is appealing after being found guilty of discrimination against Moroccans during a 2014 election rally, when he asked supporters whether they wanted "more or fewer Moroccans in your city and in the Netherlands".
When the crowd shouted back "Fewer! Fewer!" a smiling Wilders answered: "We're going to organise that."
Wilders's lawyer Geert-Jan Knoops had called on Thursday for the appeal to be postponed because prosecutors have refused to probe Democracy party D66 leader Alexander Pechtold for recent comments against Russians.
"I've still yet to meet a Russian who admits his mistakes," Pechtold told the public broadcaster NOS in February reacting to the shock resignation of the foreign minister who lied about meeting Russian President Vladimir Putin.
"The comments by Mr Pechtold and Mr Wilders are legally comparable," argued Knoops. "If one of them is prosecuted, the other should be as well."
The appeal judges refused to postpone the case, saying the "decision on whether to prosecute a person or not lies with the prosecution service. It is not the role of the court."
But the Amsterdam court said Friday the appeals judges had not "sufficiently supported" their arguments, and that Wilders was "justified in his fears of bias."
It acknowledged there were certain "parallels" between the comments by Wilders and Pechtold which "cannot be ruled out in advance".
A court spokeswoman said the decision meant the appeals case was now likely to be put back by six months. "They have to have time to read the dossier," spokeswoman Kiki Plugge, told the Dutch news agency ANP.