Britain's top drug adviser was fired Friday after saying that marijuana, Ecstasy and LSD were less dangerous than alcohol.
David Nutt's comments have embarrassed the British government, which toughened the penalties for possessing marijuana earlier this year over the protests of many prominent British scientists.
Nutt said he was disappointed by his sacking, telling Sky News television that it might have something to do with the upcoming general election, which must be called by the middle of next year.
"Politics is politics and science is science, and there's a bit of a tension between them sometime," he told the broadcaster by telephone.
In later comments to BBC radio's PM program, Nutt accused British Prime Minister Gordon Brown of making "completely irrational statements" about the dangerousness of marijuana.
"I'm not prepared to mislead the public about the harmfulness of drugs like cannabis and Ecstasy," he said.
A call and an e-mail by The Associated Press seeking comment from the scientist were not immediately returned.
Britain's Home Office confirmed that Nutt, a professor of neuropsychopharmacology, had been removed from his position and said it would be seeking a replacement shortly.
In Britain, drugs are classified in three different categories, with Class A the most dangerous one. Marijuana was recently upgraded to Class B from Class C, joining amphetamines, Ritalin and pholcodine as drugs whose unlawful possession could result in up to five years in prison.
But the move ran counter to recommendations made by Nutt, who has long argued that marijuana is far less dangerous than legal drugs such as alcohol, which is responsible for nearly 9,000 deaths a year in the U.K., according to recent government statistics.
Nutt argues that while all drugs are dangerous, the restrictions placed on them should be proportional to their potential harm. Britain's Home Office has rejected his advice, saying the scientific evidence is uncertain and that a message needs to be sent to marijuana users that possessing the drug is a serious crime.
The move prompted a flurry of protest from scientists — among them two former chief scientific advisers to the government. They and others wrote an open letter to the government warning that reclassifying marijuana would send confusing messages about how dangerous it and other drugs really were.
Although Nutt's views have long been public knowledge, the government seems to have been angered by a recent lecture for the Center for Crime and Justice Studies at King's College in London during which Nutt accused former Home Secretary Jacqui Smith of "distorting and devaluing" researchers' work.
In the lecture, Nutt said Smith's decision to tighten restrictions on marijuana had undermined public faith in government science.
"I think we have to accept young people like to experiment — with drugs and other potentially harmful activities — and what we should be doing in all of this is to protect them from harm at this stage of their lives," he said.
"If you think that scaring kids will stop them using, you are probably wrong."