Immigration from non-western countries costs Dutch society between €6bn and €10bn a year, according to a preliminary report by private research institute Nyfer for the anti-Islam party PVV, the Telegraaf reports on Wednesday.

The research is based on ‘conservative’ estimates of the cost of 20,000 non-western migrants, the paper says. ‘That is the number of foreigners who come here every year in order to reunite with their families. So the real cost is much higher,’ PVV leader Geert Wilders told the paper.

According to Nos tv, Nyfer officials are angry the preliminary findings have been publicised and say the final report is due to be published at the end of the month. Wilders himself has come up with the rough estimates used in the Telegraaf, Nos quotes Nyfer as saying.

The price tag shows that the Netherlands must put an end to non-western immigration, particularly in the light of the spending cuts which need to be made, Wilders said.

‘Academic research shows we can save billions if we stop or limit immigration,’ Wilders said. He commissioned the research after integration minister Eberhard van de Laan said last year the figures were not available.

The Telegraaf says the research shows non-western immigrants cost society more because they are more likely to claim welfare benefits and long-term nursing care, and are over-represented in the criminal justice system. By contrast, they are less likely to use state-funded childcare and get student grants.

A stop on non-western immigration is likely to be part of the PVV’s political manifesto ahead of the June 9 general election.

According to Trouw, it is still unclear when the manifesto will be published. Instead, the party appears to be releasing its standpoints bit by bit to generate maximum publicity, the paper says.

On Tuesday, for example, the PVV said it wanted to reduce the number of public tv channels from three to one and close down Dutch worldservice radio.

The party’s popularity has been declining steadily in the polls since the local elections at the beginning of March.