The number of drug users convicted of possessing cannabis in Sussex has fallen by almost a fifth in the last two years.

There is no evidence that the number of people using the drug has dropped and next year, when cannabis laws are relaxed, the number of prosecutions is expected to fall even further.

Sussex Police deny they have changed their policy towards cannabis users.

They warn people smoking the drug to expect to be arrested, charged and bought before the courts.

But the number of people being prosecuted in East and West Sussex for using cannabis is dropping while there are no reports that fewer people are using the drug.

The force's latest figures show 272 people were convicted last year for possession, compared with 330 in 1998 and 296 in 1999.

The official police line is that officers are upholding the law and the force is not taking a soft approach to users.

But the falling number of people arrested does reveal officers are changing the way they treat people caught with the drug.

It appears they are taking a different view of cannabis users compared with those using other drugs, such as heroin and crack.

Superintendant Graham Cox, second in command at Brighton police, admits arresting people for straightforward possession of cannabis is not a priority.

These days, police manpower is concentrated on highly addictive drugs which can cause users to turn to crime and violence to feed their habit.

Mr Cox said: "We cannot go around saying cannabis is okay but we can say it is not as serious as heroin.

"Arresting people for straightforward possession is not one of our priorities. But that is not to say we will not deal with it. Our first priority is to arrest people using heroin and dealing.

"People caught with cannabis are still arrested, photographed and fingerprinted but they may be cautioned rather than charged and bailed to appear in court, the same way first-time shoplifters are treated."

The number of prosecutions is expected to drop even further next year, following Home Secretary David Blunkett's recent proposal to reclassify cannabis from a class B to a class C drug.

Possessing cannabis will still be a criminal offence. It will remain a controlled, illegal drug.

But people caught with it could receive a warning or a caution.

They will no longer be arrested for possessing a small amount for their own use.

Mr Blunkett said the changes would enable police to concentrate on harder drugs and government ministers have said they do not believe a relaxation in the law will increase cannabis use.

Mr Cox said the police had been sent a signal by Blunkett as to where officers' priorities should lie.

He said: "Cannabis will remain a controlled drug and using it will still be a criminal offence. If you have a quantity clearly more than just for personal use, you will still be arrested.

"But the police will not go out looking for cannabis users, in the same way as officers don't go out looking for motorists who don't wear seatbelts."

Supporters of cannabis have welcomed the proposed change in the law.

They say the drug is not harmful, it relaxes users and medical tests are being carried out to establish the extent of pain relief it offers to the sick.

But others say it is a demotivating drug and can cause long-term changes in the brain.

There are also surveys which show it is the first drug used by many people who go on to become addicted to harder drugs.

So, in the future, will we see police turning a blind eye and ignoring people smoking cannabis openly in cafes, parks and on the beach?

Mr Cox said cannabis was clearly not as dangerous as heroin, cocaine or crack-cocaine but he believed it would be a serious mistake to make the drug legal.

He said: "My personal view is it would be a mistake to decriminalise cannabis altogether.

"I think it would be putting our young people through a huge experiment, the result of which we do not know at the moment.

"If we decriminalised cannabis, I do not think we could go back and change the law again if it turned out to be a mistake."

But others think the time has come to legalise a drug which is believed to be smoked by thousands of people of all ages every day across the UK.

Lewes MP Norman Baker would welcome a debate on legalising cannabis and is pleased the police are concentrating on other crimes rather than arresting cannabis smokers.

He said: "I am very concerned we have got a shortage of police officers in Sussex and I do not think it sensible for officers to be spending their time chasing cannabis users.

"They could be dealing with burglaries and violent crime."

Mr Baker disputed the claim that cannabis was a gateway drug which led users on to harder substances, such as heroin.

He said legalising the drug could mean fewer people becoming involved in harder drugs because they could buy it from dealers who sold only cannabis.

He said: "Having to buy it from a drug dealer who may also want to sell you heroin is the problem.

"If the supply chain is separated, it is a way of preventing hard drugs from entering the chain."

Frazer McEwen, of Addaction, which provides services for drug and alcohol users and has projects in Sussex, said it welcomed the fact police were devoting resources to combating harder drugs instead of cannabis.

He said: "It makes more sense. The reality is the people who have problematic cannabis use are a minority. I think the drugs that are causing the biggest problems, such as heroin, should be targeted.

"These people are causing the biggest cost to the community."