Police who ran the "softly, softly" approach to cannabis possession in a London borough will arrest people who smoke the drug in public from next week.

Lambeth police are launching an advertising campaign to mark the end of their year-long pilot scheme.

The aim of this campaign is to clearly explain to everyone in Lambeth that cannabis is illegal

Lambeth Acting Borough Commander Brian Moore

The trial - where people with small amounts of cannabis were warned rather than arrested - is due to end on 31 July.

This campaign follows Home Secretary David Blunkett's announcement that cannabis would be downgraded from a Class B to a Class C drug.

It has been argued that there has been public confusion over drugs policy following Mr Blunkett's announcement.

'Safe haven'

Officers in Lambeth will make arrests for personal cannabis possession if they fear disorder, if the drug is smoked openly, or if it is found on anyone under 17 - in line with national policy.

It has been claimed that some cannabis smokers have regarded Lambeth as a "safe haven" for smoking the drug.

Leaflets in different languages will be handed out and posters will be put in pubs and clubs.

Commander Brian Paddick pioneered the scheme

Lambeth Acting Borough Commander Brian Moore said: "The aim of this campaign is to clearly explain to everyone in Lambeth that cannabis is illegal and will remain illegal".

From 1 August cannabis would be seized and formal warnings issued, he said.

"Where aggravating circumstances apply, officers will be able to exercise discretion over whether to arrest," the officer added.

There have been claims of people being drawn into Lambeth to buy and sell cannabis because of the scheme.

More than 1,000 people have been warned for possession since the scheme began last July.

Of those, 52.7% were from outside the borough, a similar proportion to those caught in possession before the pilot, suggesting people were not flooding into the area to buy drugs, said police.