Due to an error at the immigration and naturalization service IND, between 2 thousand and 3 thousand immigrants were mistakenly exempted from taking the integration exam, State Secretary Klaas Dijkhoff said in a letter to the Tweede Kamer on Thursday. Their residency permits were also upgraded from valid for a limited time, to valid for an unlimited time.

The mistake has to do with new rules that were implemented for exemption from the exam as of January 1st, 2015. The stricter rules were not applied to everyone who asked for exemption.

According to Dijkhoff, between January 1st, 2015 and present about 9 thousand immigrants were exempted from the integration exam. Closer examination based on a sample revealed that "in about 2 to 3 thousand cases", the exemption should not have been granted because the application was measured against the old rules.

"The residency permits already issued can not be revoked due to the principle of legal certainty", Dijkhoff wrote. He added that the exemption grounds were changed on all application forms and the IND staff received written instructions about the changes.

The PVV immediately asked parliamentary questions about the matter, Geert Wilders said on Twitter