When the chair of the independent body that advises the Government on drug-related issues decided to pen an editorial in the Journal of Psychopharmacology questioning the scientific rigour of the UK's drugs policy, it is unlikely that he would have expected an irate Home Secretary to ring him demanding an apology. But that is what happened.
David Nutt, chair of the Advisory Council on the Misuse of Drugs, duly apologised to Jacqui Smith for going "beyond the scientific advice" expected of him, and was also asked to say sorry to the "families of the victims of ecstasy" after he equated the dangers of ecstasy to those of horse-riding.
The case opened a multitude of concerns and has appalled many. It raises not only questions about academic freedom and bullying, but also wider issues about whether it is appropriate for ministers to criticise independent expert advisers. How can independent experts ever give unbiased advice if they have to tiptoe around the sensitivities of a minister?
From European decisions to keep aggressively fishing when the advice says stocks could collapse to the National Health Service backing homoeopathy even though it has been shown to have no effect beyond that of a placebo, examples abound of government policies not matching considered scientific assessments.
This flies in the face of the Government's stated commitment to pursuing an evidence-based approach to policymaking and making better use of science to inform its approach - lessons supposedly learnt by Labour in the wake of the handling of the BSE crisis in the late 1980s and 1990s.
The underlying principle is that scientific advice makes for better policy: it gives the electorate confidence that the Government is doing the right thing for the right reasons.
It is not that the discrepancy between evidence and policy is new, nor that instances of success are absent, but recent confrontations raise questions about how the Government is using the advice it receives through its system of expert committees and departmental science advisers.
The frustration of scientists who do not think they are being listened to is palpable, and it is not just a domestic issue. Callum Roberts, professor of marine conservation at the University of York, explains how he is sickened by European ministers' failure to limit fishing quotas to what scientists have said is necessary to protect the seas. "The curious thing about science and fisheries is that they spend so much money getting scientists' advice and then they ignore it," he says.
Roberts recently analysed the decision-making record of European ministers over the past 20 years. He found that they overruled scientific advice on 80 per cent of occasions, and implemented quotas that were higher than the level advised by scientists more than 68 per cent of the time. Although Roberts acknowledges the pressures politicians face from fishing communities desperate to stay afloat, he argues that compromise policies will benefit no one in the long term.
In 2006, the House of Commons Science and Technology Select Committee produced a report, Scientific Advice, Risk and Evidence-Based Policy-Making, which made suggestions about how to inject more scientific rigour into the Government's policymaking processes. The committee's successor, the Innovation, Universities, Science and Skills (IUSS) Select Committee, is now revisiting the issue.
The committee is pragmatic: after all, it is made up of politicians. It accepts that scientific evidence won't always be paramount in decision-making. And it is well aware that issues outside the evidence base - such as remaining popular with the electorate, manifesto commitments and budgets - matter, too. But what they stress is that if ministers do choose to ignore scientific advice, they are clear about the reasons why.
"I accept that ministers have a right to ignore the evidence, provided they make it clear why ... and they are taking a decision for political, social or other reasons," explains Phil Willis, chair of the committee and Liberal Democrat MP for Harrogate and Knaresborough.
But the IUSS committee identifies another creeping problem: examples of where the Government, having ignored scientific advice, still claims that its policies are evidence-based.
Evan Harris, IUSS member and Innovation and Science Spokesman for the Lib Dems, cites some examples. The Government's stance on cannabis and ecstasy (see box below right), as well as its recent move to criminalise the demand for prostitution, are all populist moves cloaked in science's clothing, he says.
"As long as the Government says, 'Right, that is the evidence, but we are rejecting it in favour of a populist-based policy,' that is fine ... But when it dresses up something that is not evidence-based as evidence-based, that is worse because not only is it untrue, misleading and non-transparent, it also debases the currency (of evidence-based policy). It pollutes the faith people have in government declarations that policy is evidence-based."
John Beddington is the Government's Chief Scientific Adviser. He is responsible for the quality of its scientific advice and for giving personal briefings to the Prime Minister and Cabinet members on science-policy issues.
He has been in post for about a year and has already clashed with MPs on the IUSS committee over the more compliant approach he appears to be taking compared with his outspoken predecessor, Sir David King (see box below left).
His position is that decision-makers will consider "evidence" beyond the scientific, including economic, legal and social advice, and provided it can be "assessed and challenged", that is fine. He explains: "It is a fact of life that scientific advice is not the only evidence and is not necessarily paramount in all cases. The Government gets evidence from a whole variety of sources ... It is the simple equation that evidence-based policy equals policy based on science that I don't accept."
But it is a position that also allows the Government a bit of wiggle room - useful if a politician wants a certain policy that is based more on gut instinct than science to bear an "evidence-based" stamp.
Harris takes issue with Beddington, arguing that only published studies, in whatever field, should count as evidence. "There is opinion, there is anecdote, there are submissions, there are assertions and there is evidence, but (sometimes) all are called evidence ... I would rather have an anecdote about the minister's mother-in-law than reference to unpublished evidence that is secret," he says.
Beddington is keen to confine his role to ensuring that within his wider definition of evidence, all the scientific data are correct, up to date and presented clearly and fairly. On this, he points to successes, such as ensuring that the scientific advice on biofuels was improved.
"The bit (of my job) that I see I really have to do is make certain that the scientific advice is correct, or that if it is being misused it is challenged," he explains. "How ministers make decisions and on what evidence base they do that is another matter."
Scientists may soon be asking whether they shouldn't expect the Chief Scientific Adviser to be championing their corner a little harder.
HOW KING BENT THE RULES TO PUSH GREEN AGENDA
Sir David King, the Government's former Chief Scientific Adviser and the longest-serving civil servant in the role, says it is a "constant struggle" to keep scientific advice at the forefront of the minds of other civil servants and politicians.
"In the Government, if you are a high-up generalist, everyone will listen to you," he says. "If you are an economist, everyone will listen to you. If you are a lawyer, everyone will listen to you in your area of speciality. But if you are a scientist, (it is a case of) 'get back in your box. We will lift the lid when we want the message'."
Yet Sir David, now director of the Smith School of Enterprise and the Environment at the University of Oxford, is credited with one of the biggest triumphs of evidence-based policymaking in recent political history: putting climate change on the top of the UK's political agenda. How did he do it? By bending the rules.
He credits his success on a range of issues - including the foot-and-mouth crisis of 2001 (which underlined to Tony Blair the importance of listening to scientific advice) - to ensuring that he had the soundest scientific advice available on the threats of global warming.
For example, a study into the threat of climate change to the UK's flood and coastal defences, throwing into sharp relief the consequences of not getting global agreement on the reduction of greenhouse-gas emissions.
But Sir David also enlisted public opinion. He went out and convinced the public that there was a problem - a job traditionally outside the remit of civil servants.
"I was appointed by the Civil Service and (its) rules are that you don't go into the public domain, (but) how can you operate as Chief Scientific Adviser if you don't get the trust of the public? So it was accepted that I didn't play by those rules."
This saw him refuse to kowtow to senior officials after his famous 2004 statement that climate change posed a greater threat to the world than terrorism, although in the process he provoked the wrath of the White House and put pressure on the "special relationship" between the US and the UK.
It was after his statement, and the grillings received by the Prime Minister over whether he agreed with his top scientific expert, that the Government decided to put climate change on the top of the agenda for its 2005 G8 Presidency.
"Read into that whatever you will. Maybe I stepped way beyond the line, but I think it is the point at which there is a realisation that this is a massive problem and we will have to face up to it," Sir David says.
"Should you simply post your advice to the Prime Minister, or should you be proactive in getting your message across? I don't think there was a choice. If the evidence is not robustly put forward, we will slide backwards."
He is extremely concerned that the term of the Chief Scientific Adviser has been "downgraded" to three years - Sir David served for five with a two-year extension. He believes that this is the result of some senior civil servants' desire to reclaim power.
"The longer you stay in office, the more influence you have," he says. "By the time I left, my standing among the politicians was very high, but some civil servants felt threatened.
"(The Chief Scientific Adviser) undermines them more than the politicians. What threatens the importance of the generalist is the specialist."
THERE'S EVIDENCE-BASED POLICY, AND THERE'S POLICY ON DRUGS
There are numerous examples of government policy diverging from scientific advice, but one key area that has brought scientists and Whitehall into conflict recently is drugs policy.
The British approach, based on the Misuse of Drugs Act 1971, puts drugs into one of three categories, depending on the harm they are likely to cause, from the most harmful (A) to the least harmful (C). The higher the category, the stiffer the penalties for possession and dealing.
The policy clearly implies a scientific approach to assessment, and in line with this, an independent expert body, the Advisory Council on the Misuse of Drugs (ACMD), weighs up the published evidence and advises the Government.
But in relation to both cannabis and ecstasy, the Government has ridden roughshod over the advice while continuing to claim that its decisions are evidence-based, say scientists. The politicians are effectively saying that they are better at assessing the scientific evidence than the experts themselves.
The Government reclassified cannabis from C to B in January in light of "accumulating evidence, reflected in the ACMD report, showing that the use of stronger cannabis may increase the harm to mental health".
But in a majority decision, the ACMD advised that "after ... most careful scrutiny of the totality of the available evidence", cannabis should remain a class-C drug.
The ACMD also initiated a review of ecstasy last year to ensure that its class-A status was supported by the evidence.
Delivering its advice in mid-February after examining more than 4,000 papers, it concluded that based on the "balance of harms", it should be downgraded to class B.
The Government's rejection of the advice was swift. "Ecstasy can and does kill unpredictably ... We are not prepared to send a message to young people that we take ecstasy less seriously," it said, despite these factors being considered by the ACMD in reaching its verdict.
Colin Blakemore, professor of neuroscience at the University of Oxford, is a member of the independent UK Drug Policy Commission and co-author of a study that calls for the current drug classification system to be replaced with one that better reflects harm and is decoupled from political pressures.
He is incredulous about the cannabis and ecstasy decisions.
"I am concerned about how firm the Government's commitment to evidence-based policy is," he says. "It has a difficult problem. On the one hand it doesn't want to give the impression that it is soft on drugs ... but the decision to make certain substances and actions illegal requires justification on the basis of rational evidence."
He believes that the Government should not take its cues from certain sections of the media and the electorate that base their opinions on gut instinct rather than rationality. Rather, it should be leading, informing and educating the public, not bowing to populist pressure.
Blakemore worries that in the future ministers will want to control not only the mechanisms for sourcing expert advice and how it is used, but also the sort of advice given, by "hand-picking" scientists because of their particular philosophies, just as President George W. Bush's Administration did.
"I fear that when the Home Secretary comes to choose (ACMD members) again, (she) will be directed at finding people who will provide the evidence she wants," Blakemore cautions.