Hundreds of drug users are expected to gather at Glasgow Green next month for an event which promotes illegal substances.

Similar events in previous years have seen several people arrested for openly smoking cannabis.

Glasgow Cannabis Social Club already organises a pro-drugs rally in Glasgow every April - despite council officials refusing to green light the events at city parks.

They are now stepping up their activity with a so-called ‘community picnic/BBQ’ on July 10.

More than 400 people have indicated that they will attend and many have said they will bring drugs paraphernalia used to smoke cannabis.

Possession of the Class B drug can lead to a five-year jail sentence and unlimited fine.

The Scottish Conservatives have said the event should be nipped in the bud by police.

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Shadow justice minister Douglas Ross said: “It is extremely irresponsible of Police Scotland to let this event go ahead.

“Cannabis use can lead to all kinds of implications and cycles of offending to fund a habit which is incredibly hard to break. It can also lead to various mental health problems.

“It is simply not safe and the authorities should be clamping down on these types of events not turning a blind eye.”

The event next month promises “tents, music, refreshments, BBQ and chilled vibes” and the picture promoting it shows a hand holding a joint with a park in the background.

Groups holding events in public parks must secure permission from Glasgow City Council - but in the past pro-drugs rallies have gone ahead despite officials refusing to give the green light.

Chris MacKenzie, of Glasgow Cannabis Social Club, who said he “helps co-ordinate the events”, suggested the council has refused to engage with the group.

He said: “They did not approve any application we have submitted in the previous five years. We would like to work with them and grow the gatherings.”

A council spokeswoman said: “The council has not received an application to hold this event. However, any application to hold an event encouraging the use of cannabis, would be refused.”

A spokeswoman for Police Scotland said: “We note the comments from the shadow secretary (of state for justice) but we are not responsible for 'letting events go ahead' - this is a matter for the local authority.

“I can also assure you that any criminality will be dealt with appropriately and officers will not be 'turning a blind eye'.”