The Citizens' Assembly was established in February to examine and make recommendations on the country’s drug policy.
Home Office officials have acknowledged that the current regulations may be holding back research.
An open letter urges the government to rethink proposals for harsher drug policies.
"In terms of mental health problems, cannabis appears to be at least as safe as the legal drugs alcohol and tobacco."
Cross-party MPs and peers have backed a campaign to end 50 years of ‘drug failure’ in the UK