What exactly is a “full-throated apology”, to which we were treated by Boris Johnson in the Commons? It is clearly better than a mealy-mouthed version uttered from behind one’s hand with no obvious admission of culpability.

It is preferable to a mumbled mea culpa with fingers crossed to negate the purported intent, and more sincere than Father Jack’s sarcastic “I’m soooo sorry” in the Father Ted sitcom. But does any apology, full-throated or otherwise, really amount to anything without public contrition?

Remorse is different from simply saying sorry since the latter is easy while the former requires a specific act of repentance. This is what is lacking in the Prime Minister’s response to the disclosures that he broke the pandemic lockdown laws that he imposed upon the rest of us.

The brouhaha that has followed the decision by the Metropolitan Police to fine Mr Johnson for this peccadillo has split the country in two.

There are those who ask what all the fuss is about – the “offence” only involved a slice of birthday cake and a few drinks with work colleagues at the end of a long hard day in what was, after all, not just his office but his home. Didn’t we all transgress?

Look at what is happening in Ukraine and get a sense of proportion, they add. Removing a prime minister at a time of international crisis is dangerous and will play into Vladimir Putin’s hands. Mr Johnson has helped rally the West’s response to the invasion, including a well-timed visit to Kyiv that was greatly appreciated by its people.

All of these arguments are true but they are self-serving and miss the point, which Mr Johnson’s detractors are anxious to make. They say that this is not about cake or after-hours drinks in the No 10 garden but probity, integrity and honesty.

During the lockdowns, Mr Johnson set out the most draconian parameters restricting social interaction ever seen yet apparently did not consider that they applied to him. Or, as he claimed, he did not realise that what he was doing was in breach of the laws that his government had promulgated and parliament had passed overwhelmingly.

The reason he did not appreciate he had broken the law was because what he was doing was not by any measure criminal behaviour. It had only been made so by parliament and then enforced by diktat.

During the pandemic, my wife and I sat on a bench in the park when to do so was verboten. It was a ludicrous prohibition since we live together so who could possibly be harmed? Theoretically, we could have been fined had the police been bothered to enforce such an absurd restriction. I suppose they could still come after us, just as they have issued fixed penalty notices to Boris and others for transgressions that took place 18 months ago.

So, there is a strong element here of a law that was overly prescriptive and which criminalised behaviour that in no other circumstances could possibly be construed as villainous.

But while that may be so, say critics, Mr Johnson told everyone else they must conform, however illiberal the constraints, because not to do so risked spreading a deadly disease. Yet on several occasions he didn’t do so himself, properly judging that the risk was minimal. In the words of the Bard, he is “the engineer hoist with his own petard.”

In his statement to MPs, the Prime Minister used the word “sorry” many times. He has said it before, though not in the Commons since becoming the first prime minister to be fined in office. He reaffirmed his earlier acknowledgment that the country had a right to expect better. Are they going to get it?

The Opposition bayed for his resignation but he will not offer it, not even if he is fined again as rumour has it he will be, nor even when Sue Gray’s report finally materialises, if it ever does. He will not resign, nor (yet) be forced out, even if a photograph emerges of Mr Johnson in a party hat and a drink in each hand.

The only electorate he needs to worry about at the moment are Tory MPs and apart from a few they will stay their hand, not least because the obvious successor Rishi Sunak has had his wings clipped. In any case, does the infraction really warrant such a dramatic penalty? A £50 fine is one thing; stepping down as prime minister does seem somewhat disproportionate, though as was pointed out in the Commons, members of No 10 staff who did the same have been sacked or moved.

At this point, Mr Johnson’s disparagers say he would be resigning not because of the parties per se but because he has lied, dissembled, debased parliament etc etc. He has been exposed as someone who is cavalier with the truth and not especially cognisant of the proper boundaries of behaviour.

But this was known about Boris before the party elected him leader and the country gave the Tories an 80-seat majority in 2019. He was never a paragon of saintly behaviour, nor pretended to be one, so why has this changed anything? This has been a character trait since his schooldays.

As his Classics master at Eton reported to his father: “Boris sometimes seems affronted when criticised for what amounts to a gross failure of responsibility (and surprised at the same time that he was not appointed Captain of the school for the next half). I think he honestly believes that it is churlish of us not to regard him as an exception, one who should be free of the network of obligation that binds everyone else.”

That is Boris’s Achilles’ Heel, the sense that he thinks the law is for someone else, not him. He would fiercely dispute such an interpretation but if it comes across like that to enough voters, as polls suggest it already has, he will become a liability to his party’s election chances. And when that happens his apology will count for nought, full-throated or otherwise.

Mr Johnson needs to demonstrate penitence, not just say sorry. He need not go as far as Henry II and walk barefoot to Canterbury to atone for the murder of Thomas a Becket or wear sackcloth and a spiked cilice in a sign of abasement. But some visible act of penance is needed to show that he means it, perhaps through a large donation to charity.