Applicants to the Civil Service are, or at least were, always asked to analyse and report on a complex, but fictional, policy problem. The candidate is confronted with a batch of papers giving various interest groups’ positions, records of meetings, and so on, and is asked to recommend what the Government should do. These scenarios are carefully devised so that there are many reasonable positions and no obvious answer. If a candidate takes everything into account, they succeed; if they seize on one aspect and ignore the rest, then they fail.

As a former civil servant myself, I’m inescapably reminded of this when contemplating the Prime Minister’s position. Partygate is complicated. There are no obvious precedents. There is lots going on: the war in Ukraine, the cost of living crisis, the longer-run problems of energy security, to name just a few. And motives are mixed: some calling for Boris Johnson to go are genuinely motivated by propriety, but others have never forgiven him (or indeed me) for making Brexit happen or else just dislike him personally for reasons unfathomable to non-psychologists.

Not surprisingly, therefore, few of the current hot takes on the situation would get their authors through the Civil Service exams.

On the one hand the Government focuses on the Ukraine war as the single factor that justifies no action. “The Prime Minister has said sorry, it was all pretty minor and in the past anyway, there is an international crisis which must come first.” Equally, its opponents argue that the whole thing is reducible to one simple fact. “The Prime Minister broke a law which his Government introduced, there is no margin for discretion, he must step down whatever the consequences.”

Both propositions are unsatisfactory. An international crisis isn’t a blank cheque to justify any kind of domestic political behaviour. Equally it is unreasonable to argue that any breach of any law entails resignation. In both cases a sense of proportion is important.

My view is that at the moment the case for the Prime Minister’s resignation is not made. One fixed penalty notice simply does not justify it. But the issue is not closed down. I am a supporter of the Prime Minister. I want his government to succeed. He has got some huge things right. He can connect with people and take them with him like few others. But our constitutional rules must be observed and the political consequences must be assessed clearly. Partygate seems capable of changing perceptions fundamentally. The Government’s success in handling Ukraine does not seem to have changed Labour’s lead in the polls. Keir Starmer has been rated as the best Prime Minister consistently by YouGov since November.

To move on from this, I hope the Prime Minister will do two things.

First, he should recognise that giving correct information to Parliament is fundamental to our constitution. A Minister who deliberately misleads Parliament must resign. If it is done accidentally, then the record must be corrected.

The Prime Minister told Parliament on December 1 that “all guidance was followed completely in No.10” and on December 8 that “I have been repeatedly assured … that there was no party and that no covid rules were broken”. When the Prime Minister apologised to Parliament on January 12, he still said that “I believe that the events in question were within the guidance and were within the rules”.

These statements are obviously not correct. They need to be corrected and the Prime Minister has to tell Parliament why he said what he said. If he was misled by his team, then he must say how that happened. This is fundamental and I hope that the Prime Minister will make a statement when Parliament returns on April 12.

Second, he should use this opportunity to get ahead of the game. This week’s events are not the end of the story. The Metropolitan Police have not finished their work. It is entirely possible there will be further fixed penalties. Sue Gray’s full report remains out there. The drip drip effect of continuous criticism could easily undermine the Prime Minister further and leave Conservative voters despairing about moving on.

I don’t think the Prime Minister can any longer allow his Government to be subject to the vagaries of the Met’s uncertain and leaden decision-making. He should next week publish the Sue Gray report. He should acknowledge that there may still be further fixed penalties but that these would not now change the position established this week.

Most importantly, he should offer something his supporters can properly get behind. It is unfortunate that earlier unconvincing explanations have left many people thinking that No 10 was continually partying while the country was locked down: something which is simply not true.

Instead he should say what is surely now obvious to all.

“My team in No 10 had to keep the country going. Indeed early on in the pandemic they took significant personal risks in coming into work to do this – as my own hospitalisation vividly showed. The circumstances of No10 made social distancing impossible and these close-knit teams working together sometimes had a drink together. I am sorry that as a result a culture emerged which at times lost touch with the pressures facing the rest of the country and sometimes, with the benefit of hindsight, broke the laws then in force. I should have done more myself to stop this happening.

“I ask for your understanding for these special circumstances. But I also ask you to see this in the context of a UK effort which delivered a vaccine sooner and exited from covid measures earlier than virtually any other country. Under no circumstances will we ever lock down again. I am now focused on the international and domestic challenges and you, the British people, will have the opportunity to deliver your verdict at the local and eventually general elections into which I will lead the Party.”

I know, having worked closely with the Prime Minister, that he will find it hard to admit mistakes. But it is time to be honest and open with people. I have often heard him say “sunlight is the best disinfectant”. He’s right. Let the sunshine in, acknowledge the mistakes, and he will take people with him.