IT isn’t just partygate. The case against Boris Johnson is overwhelming. Of course his political opponents would think that. But I am not one of those. I voted for him as party leader and I cheered to the rafters when in December 2019 he guided the Conservatives to their – our – greatest electoral triumph since Margaret Thatcher was leader in the 1980s.

Yet, only two and a half years on from that, I am clear that Boris Johnson must go. Given the result of this week’s ballot of Tory MPs I do not know when or how that will happen. But I do know that it should, and as quickly as possible.

It isn’t just partygate, but we may as well start with that. It is core to conservative sensibility that those who write the rules are subject to the rules. We Tories are – or, at least, we used to be – the party of law and order. That doesn’t just mean law and order for those we disagree with, for mobs who slash the tyres of family cars or who chain themselves to concrete blocks to protest on the roads. It means law and order for everyone, including the prime minister and those who work for him.

The way the prime minister allowed his office to behave during lockdown was not just criminal – although it was that, as we know – it was profoundly unconservative. Allowing a sense to develop and grow that the rules somehow did not apply to them – that rules are just for other people – is a deeply unconservative sentiment, and it stinks.

As does the rewriting of the principles, known as the Ministerial Code, which govern how ministers should exercise responsibility and subject themselves to accountability in the House of Commons. We do not elect our governments in the United Kingdom. We elect the House of Commons. Governments emerge out of and are accountable to that House of Commons. This may sound axiomatic, but it is the very core of how our constitution works (or is supposed to work). It is the same, of course, for the Scottish Government: we don’t elect them, either. Rather, they emerge from and are accountable to the Scottish Parliament.

Yet Boris Johnson has rewritten aspects of the Ministerial Code to dilute this essential accountability of ministers to Parliament, seeking to replace it with a notion that “his” ministers are accountable to him. And, further, with a sense that he himself is accountable not so much to Parliament as to the people directly.

This is not responsible government, true to the traditions and understandings of the United Kingdom constitution. This is populism and, like all populism, it is designed, as a superficial appeal to the people directly, not to strengthen but to undermine parliamentary democracy.

I would struggle to think of a more unconservative thing for a Conservative prime minister to do, for the very point of conservatives is to preserve and safeguard those traditions and institutions which are special to us. Prime amongst all those traditions and institutions should be Parliament, and the central role it plays in ensuring that the government of the day is held properly to account. That Boris Johnson has trashed this is, to my mind, an even more compelling reason than the arrogance of partygate for him to go.

If that weren’t enough, however, there is, regrettably, more. For Mr Johnson leads a government (in name) that is refusing to govern (in fact). This is not a government. It’s a permanent campaign. Government requires resolute commitment and focus on problem-solving. Government requires leadership. We see none of that. What we see, instead, is an endless changing of the subject – politics by distraction – what political analysts call the dead cat strategy. As in: you don’t like what’s happening? Oh look! Over here! A dead cat! It’s a great way of grabbing headlines, but it’s a lousy way to run a country.

Wherever you look in public policy at the moment, the need is the same. Whether we think about energy supply, the ability of our airports to cope with soaring passenger numbers, the future of the housing stock, health and social care, or inflation and the rising tide of food prices – in all of these matters what the United Kingdom needs is public policy focused resolutely on resilience. How do we strengthen and girder our defences against the shocks, some long foreseen and others more suddenly sprung upon us, which are assaulting us just now on all these fronts?

Such would be the clear, unambiguous priority of any sound conservative administration at the moment. And yet, wherever you look in British government, there is no grip, no focus, no determination whatever to show the British people that prudent, safe, conservative policy is the way forward. Instead, there is a rush for venal tabloid headlines on migrants crossing the channel. Or there is panicked over-reaction to opposition pressure to spend spend spend and to worry about it later.

This week, a narrow majority of Conservative MPs decided that this is the best the Tory party has to offer. They are fools to have done so, and they will be punished at the next election, whenever that comes. It isn’t just partygate, serious though that is. It isn’t just the casual disregard for law and order. It isn’t even the failure to adhere to the basic building blocks of the British constitution.

More than anything else, it’s the drift. The pretence that government is a game, whose currency is a quick headline about a dead cat, rather than the sober and serious, and often (let’s face it) very boring yet essential task of ensuring that the country is more resilient, more secure, safer, and more prosperous when you leave office than it was when you arrived.

Boris Johnson is not merely failing as a prime minister. He’s failing as a Conservative. And that’s why this Conservative thinks his time is long since up.

Adam Tomkins was a Conservative MSP for the Glasgow region from 2016 to 2021