Brighton MP Caroline Lucas is to listen to arguments put forward by a group in favour of using cannabis for medicinal purposes.
She speak at tonight's launch meeting of the United Patients Alliance and hear evidence about why the drug can be of benefit to those with health issues.
There is an ongoing debate about the use of cannabis to treat conditions such as multiple sclerosis, and provide pain relief.
Guest speakers and medical cannabis patients will talk at the event on how the drug has improved their quality of life. It takes place at the Brighthelm Centre at 7.30pm.
Ms Lucas, the Green party MP for Brighton Pavilion backs a carefully regulated assessment into cannabis being permitted for medicinal purposes.
She said: "It’s vital that drugs policy is driven by an evidence based approach and I look forward to hearing more about the evidence about the medicinal benefits of cannabis, which has looked at the experience of some states in the US, where there has been regulated supply to meet medical need under strict regulation."
Also speaking at the event, Professor David Nutt, who has campaigned for Dutch style cannabis cafes. He thinks if they were introduced, it would lower the nation's alcohol problem.