Street dealers caught with heroin, cocaine or thousands of pounds worth of cannabis could avoid jail under new guidelines for judges which come into force next month.
Offenders who play a lesser role in gangs could be handed community sentences when they come before the courts.
This could include low-level dealers caught with 6kg of cocaine, which could sell for tens of thousands of pounds, and some heroin and cocaine dealers deemed to have played only a minimal role.
So-called drug mules, who bring narcotics into the country and are often exploited by organised criminals, could also get a community sentence if caught with relatively small amounts of class C drugs.
But the Sentencing Council, which sets the guidelines for judges, said those used to bring class A drugs into the UK, a more typical offence, would still face jail, but were likely to serve less time behind bars than at the moment.
And offenders who were employed by someone else to import or export drugs regularly for profit would face even tougher sentences, up to the maximum of life in prison.
It is the first time all courts in England and Wales have been given a comprehensive guideline setting out how the role of the offender and the quantity of drugs should influence sentencing.
Under the new guidelines, drug mules, often women forced or tricked into the crime, could face a starting point of six years if deemed to be playing a "lesser role" in bringing in up to 1kg of heroin or cocaine.
But this could increase to 11 years if, instead of playing a lesser role, the offender was one of the leading figures, perhaps organising the crime or making substantial profits.
Tougher sentences could also be handed down to key players guilty of producing drugs on a large scale.
And for the first time, anyone dealing to children or teenagers under 18 would also face tougher treatment by judges.
Lord Justice Hughes, the council's Deputy Chairman, said: "Drug offending has to be taken seriously.
"Drug abuse underlies a huge volume of acquisitive and violent crime and dealing can blight communities.
"Offending and offenders vary widely so we have developed this guideline to ensure there is effective guidance for sentencers and clear information for victims, witnesses and the public on how drug offenders are sentenced."
He added: "Drug dealers can expect substantial jail sentences."
The national drugs centre Release, the International Drug Policy Consortium (IDPC) and the Transnational Institute of Policy Studies (TNI) said the guidelines would see the starting point for drug mules reduced from 10 years to six years in most cases.
As of June 2010, 1,549 of the 11,071 people in prison for drug offences were being held on charges of unlawful import or export, Ministry of Justice figures showed.
Some 15% of women in prison in England and Wales are foreign nationals, with most women jailed for drugs importation coming from Nigeria, Jamaica and South Africa, the Prison Reform Trust campaign group said.
Juliet Lyon, the group's director, said: "The new emphasis on holding organised criminals to account, rather than allowing the burden of punishment to fall on vulnerable people, many of whom have been coerced into offending, is both timely and welcome.
"In the light of these new guidelines, the Prison Reform Trust calls on the Government to review the sentences of all those who have been trafficked into acting as drug 'mules' and are currently languishing for long years in British jails."
The Association of Chief Police Officers (Acpo) added that the guidelines offered police "consistent guidance yet still provides the courts with flexibility to deal with each case on its own merits where appropriate".
Martin Barnes, chief executive of DrugScope, said: "DrugScope has long had concerns about the numbers of women involved in low-level supply and other offences as a result of violence and intimidation: far too many end up in the courts and in our prisons.
"We believe that these guidelines are a positive step forward in addressing this problem."
He went on: "As a result of these changes to the guidelines, we are hopeful that more judges will feel able to refer people who are dependent on drugs for treatment as part of a sentence for a drug-related offence.
"Good quality treatment is instrumental to breaking the cycle of drugs and crime which blight the lives of many individuals and communities."
Vicki Helyar-Cardwell, director of the Criminal Justice Alliance, a coalition of more than 60 organisations, added: "It is absolutely right to curb the draconian sentences currently given to drug mules.
"These sentences are frequently disproportionate and unjust, while there is no evidence that long sentences act as a deterrent in these cases."
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