Sir John Redwood is MP for Wokingham, and is a former Secretary of State for Wales.

Advisers advise, Minister decide.  In a flourishing democracy elected officials make the decisions in government, based on the best possible advice from unelected officials and a supporting team of experts. Some of the experts are inside government, some hired in for the task, and some from outside offering free advice. The Minister has the difficult task of deciding what advice to request and take seriously, and the even more difficult task from time to time of telling a particular group of experts they are wrong.

Let me hasten to reassure my readers that I think there are some great experts around. If I were to fall seriously ill I would want a good doctor to advise and treat me. If I want to extend my house I want a good structural engineer and builder to turn my vision into a strong and practical construction. I like my experts to be learned, to be specialist in their field. Above all I want them to have a high probability of being right for me to trust their judgement.

It has been fashionable for many years to claim that we will be better off if more matters are settled by experts, free from political interference. Cries go up. Let us settle interest rates and banking rules far away from Ministerial scrutiny in independent central banks. Let us decide flood protections and water management in independent environmental agencies. Let us decide fishing rules in closed meetings with expert advice in the EU rather than making them at home, given the cross-border migrations of fish and boats.

The truth is that in many fields experts have let us down, coming to wrong conclusions and making or influencing  bad judgements. Independent central banks watched helplessly or encouraged banking collapses in 2008-9. Their bad actions and inactions followed an agreed common set of mistakes on both sides of the Atlantic in allowing too much bank credit and geared derivatives to come into being.

The UK Environment Agency presided over the mass flooding of the Somerset Levels. The Common Fishing Policy degraded our fish stocks and demolished much of our fishing industry. These and other errors turned people off experts who get things wrong. It has not turned them off the idea that good experts have vital information and judgements to contribute to secure our lives.

In each of these cases, the elected officials, the politicians, had to take back control or intervene to make things better. In 2008-9, the UK Chancellor and other leading finance ministers rightly made the central banks cut interest rates faster and earlier than they planned to start to turn the crisis. They followed up by taking a role in the decisions over Quantitative easing which became an important part of the recovery policy.

The flooding of the Somerset levels led to Owen Paterson, then the Secretary of State, bravely rejecting the no pumps/no dredging policy of the Environment Agency, insisting on the previous policy which successfully controlled water levels in subsequent periods of heavy rain. The UK public rose up against the Common Fishing Policy and other similar laws and decisions of the EU and demanded their return to UK democratic control in the referendum.

Today, we witness another important intersection between experts and elected officials over the handling of the pandemic. So far the constitutional niceties have been observed. The Government relies heavily on internal expert opinion, which in turn draws on the latest knowledge and research globally through the World Health Organisation. The Prime Minister and Health Secretary make the final decisions based on  the best scientific advice.

Some say the expert advice should take over and drive the whole process. That is to misunderstand the nature of the advice, the state of the science and the complexity of the issues to be decided. The official spokesmen explaining the medical and scientific background rightly stress what they do not yet know as well as what they know. The scientific community cannot yet provide a specific treatment for this  disease nor a vaccination against it.

Knowledge is still imperfect about how long it can be in someone before symptoms show, how it is transmitted, why it is sometimes very dangerous but normally not for a younger healthy person, whether it can be caught twice by the same person, and whether someone does build immunity to it by having it. This means there is plenty of scope for expert disagreement about what the right response must be.

The elected officials need to follow the public interest by adding to the discussion their understanding of what the public will accept. Politicians have to assess  which controls are realistically enforceable, how people might get round them,  and what the right balance is when considering economic damage on the one hand and the need to restrict activity to control the virus spread on the other.

Many of these matters are judgements, to be made on the basis of imperfect information. There does need to be debate amongst experts as they rush to reach a fuller understanding of what we are facing. The advantage of the elected official making the ultimate decision is one of accountability. Through Parliament, public debates and the wider media our elected officials are much more exposed to the day to day realities of the wider public who need to live under the  new controls and need to have confidence in them.

As someone who has been a senior adviser in government seeking to influence Prime Ministerial decisions, and a senior Minister in government making decisions, and as someone who has been an executive chairman of a company and a professional adviser to business, I am well aware of the need for good advice.

I am also well aware of the need for the ultimate decision to be made by someone who can weigh the wider context and seek to prioritise the often conflicting aims of policy. It is wrong to say this can all be settled by the science and the decisions all taken by the epidemiologists.

We need them to be on top form and to be influential, but the Prime Minister has to remain the ultimate accountable official responsible for the final judgement. He and his personal advisers have both to decide which scientific and medical advisers are offering us the best chance of combatting the virus successfully, and to decide how much collateral damage the economy can withstand as they respond to the medical issues.