Eric Carlin has become the seventh government drugs advisor to resign, causing further embarrassment to ministers over their handling of drugs policy.
Mr Carlin said that the ban on the “miaow-miaow” party drug this week was rushed through as a politically motivated attempt to make the Government look tough prior to the election.
In a letter to Alan Johnson, the home secretary, Mr Carlin said the decision was "unduly based on media and political pressure".
He added that he was “extremely unhappy” with the way the drugs council operates.
The resignation will not stop mephedrone – linked to 26 deaths in Britain – being added to the list of illegal drugs within a fortnight, classified as a Class B drug.
However the Government’s key relationship with the ACMD is in tatters, and several other advisors are also understood to be considering their positions.
Mr Carlin is the seventh expert to resign from the committee since October, when the controversial chairman Professor David Nutt was sacked.
Two members, Les King and Marion Walker, quit immediately in protest.
Mr Johnson met the ACMD a month later to reassure the expert panel of its independence, but was faced with three more resignations from council members who were not convinced.
Dr Polly Taylor, a consultant veterinary surgeon and long-standing member of the council, then offered her resignation to the home secretary on the eve of mephedrone being banned.
Lest, however, you think that the Tories will be even millimetrically better on this shit, you may wish to reconsider:
Chris Grayling, the shadow home secretary, said: “The relationship between the government and its drugs advisory council has become utterly shambolic.
"The decision on Mephedrone was the right one, but this latest resignation suggests pretty clearly that the Home Secretary has been completely unable to restore his relationship with the experts who advise him.”
No, Mr Grayling, you utter cockspanner, it's precisely because the fucking experts that are so fucking vaunted in this fucking shit hole of a cuntry were completely ignored and run roughshod over, that they're resigning in fucking droves.
As you will find out yourself in the unlikely event of a fucking Tory victory.
You useless fucking oxygen thief.