Expanding the experiment to regulate marijuana production to include part of Amsterdam may not now happen, given a majority of MPs are opposed to the idea.

Ten cities have been earmarked for the trials, which began in Tilburg and Breda at the end of last year. But the right wing and Christian parties are against any expansion of the project, it emerged during Wednesday’s parliamentary debate. 

The government had hoped to include a big city to assess the impact of regulating the supply chain in a more complex area but all five said no. Amsterdam’s mayor later suggested adding Amsterdam Oost to the 10 others.

“We don’t see any reason to add an 11th council to the experiment,” said NSC MP Daniëlle Jansen. Her party, she said, had “serious doubts” because it was just “part” of a city. If the BBB and Denk, which were not at the debate, also vote against, then Amsterdam will be out.

Meanwhile, cannabis café owners in Amsterdam Oost have written to parliament expressing their disappointment at the way the experiment will be run, the Telegraaf reported. In particular they are concerned at no longer being allowed to sell Moroccan hashish, which is part of Moroccan culture, the paper quoted the letter as saying. 

In the first phase of the trial, cannabis cafes or coffeeshops can continue selling “illegal” marijuana as well as regulated products and not all outlets will have to take part.

Later, all coffee shops in the cities where trials are taking place will be restricted to legal marijuana products only.

The experiment aims to assess if cannabis cafes, or coffee shops, can operate legally by buying the soft drug from official growers. Coffee shops are currently licenced by their local authority but buy the drug on the illegal circuit.

Amsterdam is the only city in the Netherlands where everyone over the age of 18 can buy cannabis products from a coffee shop. Elsewhere, only locals residents can use their facilities.

Ten growers have been given licences to provide exclusive produce to coffeeshops in Breda and Tilburg, and then to coffeeshops in another eight municipalities this year, including Groningen and Maastricht.