- The Commons Home Affairs Committee have said ministers could learn from the experience of Portugal, the US and Uruguay.
- In Portugal drugs have been "depenalised"- with possession of small amounts not subject to criminal penalties, even though they remain illegal.
- In Washington and Colorado in the United States cannabis is being legalised.
- In Uruguay a state monopoly of cannabis production and sale is being proposed.
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The talks descended into crisis on Friday when Canada's trade minister Chrystia Freeland walked out of meetings.
Police in New York are still investigating what the substance is and whether it could be harmful.
The Sherlock actor made the comment while he received an award for his humanitarian work.