The Government announced today that it will not make changes to two key areas of drug policy.
Revisions to the way drugs are classified will not go ahead despite claims that the current system should be scrapped.
A reorganisation based on the damaging effects of substances could have seen tobacco and alcohol ranked alongside heroin and crack cocaine.
In a simultaneous announcement, the Home Office said it will not make any changes to the thresholds at which individuals could be prosecuted for dealing.
Officials said there was no agreement on where limits should be set on how much drug an individual could hold for personal consumption.
The Home Office said it is committed to the current drug classification system, which rates drugs according to medical and social harms, as well related crime.
It was responding to a Parliamentary report from earlier this year that called for the current drug classification system to be scrapped.
The Science and Technology Committee said the system was based on "ad hockery and conservatism" and substances should be rated on the basis of health and social risks.
Alcohol and tobacco should also be included in the ratings to give the public a "better sense of the relative harms involved", their report said.
Committee chairman Phil Willis MP said the current classifications were "riddled with anomalies" and "clearly not fit for purpose".
But officials said education, enforcement and treatment remain their key drug strategy priorities.
Home Office Minister Vernon Coaker said: "It is important that there is a coherent system in place to categorise drugs and determine the penalties for their manufacture, possession and supply.
"I believe that the existing classification system does this effectively, allowing for clear and meaningful distinctions to be made between drugs.
"I have spent the past few months meeting frontline police, victims of crime, drug addicts and others involved in the criminal justice system.
"None of them have raised the classification system as a concern that affects them with me.
"I believe it is vital that we focus our energies on tackling drugs supply, getting more drug users into treatment and educating young people about the dangers of drugs."
The Government said it will continue to focus on the serious harm caused by Class A drugs, such as the risk of overdose and disease, addiction and associated acquisitive and organised crime.
The Government said it will keep a decision on setting a threshold on drug possession levels "under review".
The Association of Chief Police Officers (ACPO) said current legislation is adequate for enforcement.
Mr Coaker said: "The Home Secretary has already committed to devolve more responsibility to frontline services such as the police.
"I am extremely impressed at the effective work the police have done in tackling drug related crime and don't want to introduce any measures at this time that might increase the burden on forces and affect their performance.
"The Government's drug strategy is directing thousands of people out of crime and into treatment every week and this is benefiting communities across the country."
Martin Barnes, chief executive of charity DrugScope, said he was "extremely disappointed" that the review of drug classification will not go ahead.
He said: "Concerns about and criticism of the classification system will not go away and are likely to be repeated time and again when the current 10-year drug strategy is reviewed before it ends in 2008.
"The current system was introduced 35 years ago and during that time we have seen a significant increase in levels of drug use and drug-related harms.
"There is no silver bullet, no ideal system, but the government should not be afraid to lead a debate as to whether there are better alternatives."
Mr Barnes backed the decision to abandon plans to introduce thresholds at which individuals would be considered to be supplying drugs.
He said: "There has been considerable confusion about the purpose of the thresholds and a lack of agreement on the appropriate amounts.
"Suggestions that only five ecstasy tablets or five grams of cannabis would trigger the serious charge of intention to supply caused alarm and would have seriously hampered police discretion."
Last November the Home Office publicly floated plans to set a "500-spliff" limit for a personal stash of cannabis, as well as thresholds for other drugs.
But in June a leaked document suggested the plans would be significantly tightened up, slashing the limits to as little as one hundredth of the original level.
It was reported that ministers were minded to set a threshold of five grams for cannabis - compared with the half-a-kilogram of leaf cannabis suggested last year.
Five grams is enough to make about 10 cannabis cigarettes, according to experts, compared with approximately 512 average-strength joints which can be rolled with half a kilo.
The leaked document also said ministers wanted to set the following limits for drugs including heroin, cocaine and amphetamines.
Setting a formal limit would have affected how many people were prosecuted as drug dealers, and how many escaped with lesser charges.