Geert Wilders launches his election campaign
Amid tight security, Wilders made a rare public appearence in his Freedom Party's stronghod of Spijkenisse, where he shook hands with supporters and posed for photographs.
Opponents of the far-right candidate – who has promised to shut down mosques and ban the Koran – stood holding placards bearing pro-immigrant slogans.
Wilders told the crowd: "There is a lot of Moroccan scum in Holland who make the streets unsafe.
"If you want to regain your country, make the Netherlands for the people of the Netherlands again, then you can only vote for one party."
It is not the first time Wilders has targetted Moroccans – he was convicted in December of inciting racial discrimination for comments made in a 2014 post-election speech.
The populist has been dubbed the "Dutch Trump" for some of his extreme policy announcements, sometimes going even further than the US President himself.
This week he promised to de-Islamisize the Netherlands, and said he would change the country's constitution if necessary.
Mr Wilders told AP: “A constitution is not something that is (set) in stone and can never be changed.
“It’s alive as a society is alive and we are now being threatened by mass immigration and Islamisization and what I see as the toxic combination of mass immigration from Islamic countries."
He also described Islamic faith as "possibly more dangerous" than Nazism – comments which were heavily condemned by Spior, an Islamic organisation representing 70 mosques and Islamic groups in the Netherlands.
Geert Wilders called Moroccans 'scum' during his campaign launch
Wilders seldom goes out in public and when he does is surrounded by a huge security entourage, due to frequent death threats and attempts on his life.
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But his Freedom Party leads in polls with 17 percent, although the pro-business liberals of Prime Minister Mark Rutte have closed the gap on Wilders to a percentage point by matching some of his anti-immigration rhetoric and getting an electoral boost from a surging economy.
However all mainstream parties, most recently and notably Rutte's party, have ruled out working with Wilders because of his anti-Islam stance.
But even if he does win, Wilders would struggle to form a government since most major parties have ruled out joining a coalition with him.
The next Dutch parliament is unlikely to support policies such as quitting the European Union.
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