Anti-Islam politician Geert Wilders is hoping to use a 150-year-old law to start legal proceedings against Integration Minister Eberhard van der Laan for failing to answer the Freedom Party’s questions on the cost of immigration.

Mr Wilders’ Freedom Party asked the minister to work out the cost to the country of immigrants on an individual basis. Ministers are constitutionally obliged to honour MP’s requests for information, and Mr Van der Laan promised to provide Mr Wilders with answers. He duly provided the Freedom Party with 30 pages of raw data, but refused to translate the information into the kind of cost-benefit analysis the Freedom Party wanted. “We do not keep accounts on the value of human beings," said Mr Van der Laan.

Speaking on Dutch breakfast television on Monday, Mr Wilders said that five Freedom Party MP’s have now written to the speaker of the Lower House calling for an investigation. The Freedom Party wants to have charges brought against the integration minister based on legislation dating from 1855, which says that ministers have to abide by the constitution and provide information.

Meanwhile, Forum, the Institute for Multicultural Development, commissioned its own study on the cost of immigration last month from economist Peter Nijkamp at the Free University in Amsterdam, in an attempt to take the wind out of the Freedom Party’s sails. Mr Nijkamp said he was amazed such data should be seen as a taboo.