Launched last week by Wilders' Freedom Party, the website calls on citizens to report "Central and East Europeans ... for general nuisance, pollution and labor market displacement."
Diplomats from Bulgaria, the Czech Republic, Estonia, Hungary, Latvia, Lithuania, Poland, Romania, Slovakia and Slovenia have issued an angry response in an open letter, asking the Dutch government to "distance themselves from this deplorable initiative," which they say is "clearly discriminatory."
The diplomats said the website would not help solve some of the issues caused by migration of citizens from eastern EU countries.
"Rather, it encourages negative perception of a particular group of EU citizens working in the Netherlands," the letter said. "The statistics clearly show that our fellow citizens contribute significantly to the growth of the Dutch economy and the Dutch budget. The truth also is that our citizens do not take jobs from the Dutch nationals."
EU Justice Commissioner Viviane Reding and EU Digital Affairs Commissioner Neelie Kroes, who is Dutch, have criticized the website. In comments posted on social networking site Twitter, Kroes mocked the Freedom Party's initiative.
"Ridiculous to think that denouncing others on a website will make Netherlands or EU a better place," Kroes wrote. "What next? Your wife annoys you? Forget Valentine's Day, log on and denounce her!"
The Freedom Party is the third largest in the Netherlands and is a key backer of the minority right-wing government of Prime Minister Mark Rutte.
Wilders was recently acquitted of hate speech charges after he described Islam as a violent religion and made comparisons between the Koran and Hitler's "Mein Kampf."
dfm/ncy (AFP, AP)