The Home Secretary Alan Johnson is considering sacking his top expert drugs adviser following criticism of the government's decision to reclassify cannabis.

Professor David Nutt, who chairs the Advisory Council on the Misuse of Drugs, yesterday accused ministers of devaluing and distorting evidence by their decision to move the drug back up to Class B from C last year (see my previous post, Scientists v Politicians: Round 3).

An e-mail sent to the BBC by an official in the Home Office this morning says that "yesterday's coverage may have some serious repercussions for Prof Nutt and his position as chair of the ACMD".

The note goes on to say "discussions are being had (at) a very high level regarding this issue and a decision will be taken early next week."

Professor Nutt knew nothing about the moves to dismiss him when I spoke to him earlier today, but seemed resigned to the possibility. "They are bound to be considering that," he told me, "thinking about the least worst option."

"I think the issue is whether I am straying into the realm of policy," he suggested. "I personally don't think I was."

A source in the Home Office tells me that "the writing is on the wall" for the scientist, although no decision has yet been made.

On last night's Question Time, the former Home Secretary Jacqui Smith was asked about Professor Nutt's view that the process by which she increased the penalties for cannabis possession last year was "highly politicised".

Dimbleby: "You don't have much time for the head of the advisory council..."

Smith: "Frankly, no."

Dimbleby: "Why not?"

Smith: "I think, actually, this foray into policy is not what his job is about. His job is to advise and my job as home secretary was to decide."

If Alan Johnson does sack the professor, there is likely to be a strong reaction from some in the scientific community who may well argue that this is an attempt to silence independent academic discussion.

However, the online Sun columnist Jon Gaunt argues that the expert advisor has overstepped the mark:

"It's perfectly acceptable for Nutt to have these discussions in the cosseted world of academia but it is totally irresponsible for him to pontificate in public and in his position as Drug Tsar. He must be sacked immediately."

Also appearing on Question Time last night, Liberal Democrat MP Lembit Opik, accused Jacqui Smith of bowing to a tabloid agenda when it comes to drugs policy.

"What's the point of paying people to give you expert advice if you then run your government policy through the red tops?"

Professor Nutt waits to hear his fate.

