A Capetonian believes that homes made of cannabis are an answer to South Africa's housing problem.
André du Plessis plans to hand over a petition to the office of the Public Protector on Friday. He is also co-ordinating a march through the city centre on Saturday morning.
The petition describes cannabis - a plant genus that includes what South Africans know as dagga - as "a sustainable agricultural option for economic empowerment" and calls for government departments to participate in a forum to develop policy "more in keeping with international trends".
Du Plessis said on Wednesday that that cannabis mixed with lime was currently used for home construction and insulation in France and Germany, and that it had a long history as a building material.
The 1 500-year-old Hagia Sofia basilica in Turkey was "the world's longest-standing dagga building", he said.
He has built a scale model dome of cannabis in a Newlands back garden, which has proved strong enough to take the weight of a 4x4 vehicle.
But for a full-scale prototype, he needs three tons of the green stuff. He had been trying for years to get the Agricultural Research Council, which has a licence to grow cannabis, to work with him.
"They still haven't delivered one kilogram that I can use to test with," he said.
"All I'm trying to do is build some affordable housing for those people who live in shantytowns. That's my angle on it."
Du Plessis also said cannabis was the cheapest way to get patients with full-blown Aids to eat again.
He said the petition had been signed by people ranging from politicians and surgeons to "folk from the street".
There were also one or two dagga growers on the list.
"They have put their names down, but they haven't put a contact address," he said. - Sapa