Birmingham is no longer the cheapest place in Britain to buy hard and recreational drugs according to new research.
The cheapest ecstasy pill found last year was £1 in Birmingham but the latest survey found pills for 50p in Portsmouth and 80p in Cardiff.
Conservatives accused the government of losing the war on drugs following the publication of the Druglink Street Price Survey 2005.
The charity also revealed the drug ketamine - best known as a horse tranquiliser - is rapidly gaining popularity and has become a significant player in the UK drugs scene.
The powerful hallucinogen - nicknamed "special K", " tekno smack" and "vitamin K" - is a legal drug.
The charity's Druglink magazine found ketamine, which was previously a fringe drug in the gay clubbing scene, on sale in eight out of 15 British towns and cities it surveyed.
Magazine editor Harry Shapiro said: "The emergence of ketamine as a key substance of choice is an entirely new phenomenon since we last carried out the survey in 2004, when it didn't figure at all."
Shadow home secretary David Davis said: "This shows that far from winning the war on drugs Labour haven't even begun to fight it.
"The fact that an ecstasy tablet can be bought for less than a can of Coke is a shocking indictment of Labour's absolute failure to tackle the scourge of drugs."
Birmingham drug treatment worker Neil Venables said: "Ecstasy pills contain less MDMA (the active ingredient) than they used to and so it is more of just a stimulant than something that alters your state of mind.
"People aged 18 to 25 are taking ketamine for a more trippy night out. You can spot them on the dance- floor because they're not dancing, they're sitting down in a bit of a vegetative state."
Nottingham drugs worker Pete Hurd said: "Ketamine has now established its place alongside the usual dance scene drugs like ecstasy.
"It's popular in pre-club bars and has a big following in both gay and straight clubs.
"It is being taken with other dance drugs by middle class people who like to party hard at the weekend and then go back to work in the week," he added.
The survey also found drug dealers are offering "two-forone party packs" of heroin and crack, including special £5-abag offers for prostitutes.
For example, London dealers were commonly offering two £10 bags of heroin and a £10 bag of crack for £25.
DrugScope said the survey, carried out among 40 frontline drug services in July, provides the most up-to-date information on average UK street drug prices.
It reported that the price of heroin in Sheffield had halved to £25 a gram, making it the cheapest in the UK.
Mr Shapiro said: "As this survey shows, we are seeing significant regional variations in both drug usage and drug markets across the UK, with certain towns emerging as 'hubs' supplying the local region."
Ketamine was invented in the Parke-Davies laboratories, Michigan, US, in 1962.
Despite its reputation as a horse tranquilliser it was used in US field hospitals in the Vietnam war and is still used medically for humans under the brand name Ketalar.
Doses of 100mg lead to euphoria and energy rushes.
Higher doses of 200mg and above make users descend into hallucinations.