Amsterdam has to participate in the national experiment with regulated cannabis cultivation. If the Dutch capital, with the largest coffeeshop market in the Netherlands, does not participate, the experiment will fail, mayor Femke Halsem said in a city council debate on the issue on Thursday, Het Parool reports.

Halsema previously wrote a letter to the government asking that the strict conditions for the experiment be adjusted for Amsterdam. The current conditions make it impossible for the capital to participate.

The size of Amsterdam's cannabis market - with 166 coffeeshops - is a problem. The government determined that the experiment will cover all coffeeshops in participating municipalities. But with so many coffeeshops in Amsterdam, that is basically impossible. Halsema is concerned that the sudden cancelation of all these coffeeshops' backdoor suppliers could turn violent.

The Amsterdam mayor also criticized the limited diversity of cannabis and hashish included in the experiment - 15 to 20 different types of hash and weed. The current offer under the tolerance policy includes hundreds of different varieties. She worries that limiting the offer that much will result in more street dealing.

"We realize that it is of great importance that Amsterdam takes part", Halsema said in the city council on Thursday. "If we do not take part, the experiment is completely hopeless in advance." On the advice of the D66, Halsema will ask whether Amsterdam can participate in the cannabis experiment with a district, instead of the whole municipality. "This is a final gesture, the office of mayor and aldermen realize that it is very important that we participate."