Government drugs adviser Keith Hellawell today announced his resignation in protest at the proposal to reclassify cannabis.

Mr Hellawell, the former Drug Tsar who is now a part-time adviser to the Government, also attacked Government "spin" for relaunching its 10-year drugs strategy.

He said he had written to Home Secretary David Blunkett to inform him of his resignation but had so far had no response.

He said on BBC Radio 4's Today programme: "It's moving further towards decriminalisation than any other country in the world.

"I have resigned over this issue and over the issue of spin."

Mr Hellawell, who was a chief constable before being appointed by Tony Blair to address international drugs issues, added: "I'm against it because of the message it gives. It's actually a technical adjustment which in the reality of the law doesn't make a great deal of difference.

"But it's been bandied about by people as a softening of the law. It is a softening of the law and it's giving the wrong message.

"It's a personal initiative of David Blunkett. I don't know where he got his advice from, he certainly didn't get it from me.

"But there is no evidence at all to indicate that there is any change in the system.

"Even his own committee says that cannabis is a dangerous substance, there's an increase in use among young people, there's an increase in people who are seeking treatment for the drug, and even in that report it does recognise that there is a link between cannabis and harder drugs.

"So why on earth, when there are these problems, we change our message and give a softer message, I do not know."

Mr Hellawell said he was "pleased" that the police were against the proposals, adding: "It would be putting cannabis into a category of other drugs which are legally available in other circumstances.

"The reality is that the police take no action against people who have as a personal possession of drugs in Category C. They just don't prosecute, it's just an area that they leave alone."

Criticising what he called Government spin, Mr Hellawell said: "Also today I understand, although I've been kept out of the discussions on this, there's going to be a re-launch of the (drugs) strategy."

He had become more concerned that the Government was not addressing the strategy, he said, adding: "There is just a sort of a re-packaging, a re-spinning of the issue to appear as if something has been done, and this is causing a great deal of problems on the streets, it's causing a great deal of problems for parents who just don't know where they are.

"Drugs are so important to all our families in this country, the politicians should not make political play out of it and should not take advantage by making political statements."