Dutch prosecutors have begun summing up their case against populist anti-Islam lawmaker Geert Wilders in his hate-speech trial that pits freedom of expression against the Netherlands' anti-discrimination laws.

Prosecutor Wouter Bos stressed Wednesday that the decision to put the popular but controversial Wilders on trial for anti-Moroccan statements in 2014 was driven by the law and not personal opinions.

Bos says the decision "is based on a thorough analysis of the law, the specific circumstances of this case and the use of all the expertise of the prosecutor's office. Nothing more, nothing less."

Wilders, whose Freedom Party is riding high in opinion polls ahead of parliamentary elections in March, is refusing to attend the trial, labelling it a political witch hunt.