Ministers will publish their proposals for the planned experiment with legal marijuana cultivation by the summer, justice minister Ferdinand Grapperhaus has told parliament in a briefing.

The new government pledged to experiment with cultivating marijuana in an effort to remove the grey area between illegal supply and licenced cannabis cafes or coffee shops, where small amounts of marijuana can be bought for personal use.

A specialist commission is due to report on how the experiment should be carried out by May 31, allowing Grapperhaus and health minister Bruno Bruins to take a final decision on what form it should take.

The experiment itself will run for four years in six to 10 local authority areas. After that, the trial will be wound down and within six months the situation will be as it was before the trials. Independent experts will then evaluate the results, Grapperhaus said.

By November last year, 25 of the Netherlands’ 380 local authorities had come forward to say they wish to take part in trials to regulate marijuana production.

They include Breda, the Noord-Brabant town of Cuijk, and Rotterdam, where mayor Ahmed Aboutaleb wants the experiment to cover distribution as well.

Breda mayor Paul Depla told NOS last year he hopes that the government will opt for as many different sorts of production plan as possible ‘so we can choose the best one for regulated growing,’ he said.