The mayors of 25 Dutch local authority areas have increased their pressure on the cabinet to allow experiments with regulated marijuana production.

The initiative is being powered by the mayors of Eindhoven and Heerlen and a Utrecht alderman, the Volkskrant said.

The manifesto is a reaction to justice minister Ivo Opstelten’s decision not to approve experiments with regulated growing. He said on Thursday this would be illegal and would not solve the problems.

Eindhoven mayor Rob van Gijzel hopes by acting together, the councils will be able to persuade the minister to change his mind. Local councils are very concerned about the health effects of illegally grown marijuana and the rise of organised crime, he said.

At the moment it is illegal to grow marijuana. This means there is a grey area between the official policy of turning a blind eye towards possessing small amounts of marijuana and the supply to cannabis cafes, known as coffee shops.