AMSTERDAM (Reuters) - Dutch politician Geert Wilders called on Thursday for one of the judges in his hate speech trial to be replaced on the grounds of bias, a court spokeswoman said.

Wilders is facing charges of discrimination and inciting racial hatred at a rally in 2014 at which he led supporters in chanting they wanted fewer Moroccans in the Netherlands. He denies wrongdoing.

His lawyer has asked that judge Elianne van Rens - one member of a three-judge panel - be replaced because she allegedly showed prejudice in cutting short an expert witness who had been called to testify on Wilders' behalf.

"What terrible bias from this judge who can barely disguise her hate for the Freedom Party," Wilders tweeted. He is not attending his trial in person.

With national elections due in March, Wilders' anti-immigration Freedom Party currently rivals Prime Minister Mark Rutte's conservative VVD Party in popularity.

Spokeswoman Judy Roosen of the Hague District Court told Reuters the trial was suspended temporarily and a separate panel of judges would convene on Friday to review the request.

The case had been expected to run through to late November, with a verdict in December, but that could be delayed if Van Rens is replaced.

Requests for the replacement of judges are rare, but permissible under Dutch law.

At Wilders' previous hate speech trial in 2010, he made two such requests. The first was rejected but the second led to the replacement of the entire three-judge panel hearing his case, causing a significant delay in the process. He was acquitted in 2011.

That trial and acquittal were seen as contributing to his popularity and perceptions of him as a defender of freedom of speech.

(Reporting by Toby Sterling; editing by Andrew Roche)