A former prime minister once told me that PMQs in the Commons is an event that can only be enjoyed in retrospect, after the final whistle has blown. Even if exchanges with the opposition leader had gone well, there remained the possibility of being tripped up by a minor party leader, an opposition backbencher or a member of the ‘awkward squad’ on your own side.

Tony Blair disliked it so much that one of his first acts as PM was to cut the sessions from two a week (Tuesdays and Thursdays) to just one: a half-hour joust on a Wednesday. His prime motivation for doing so was that he knew the amount of time PMQs preparation had taken up when he was Leader of the Opposition. He concluded that devoting a similar chunk of the working week to it as prime minister would reduce his capacity to govern. But Blair certainly did still prepare intensely for his weekly battles with the likes of William Hague, eventually coining a killer soundbite (‘good jokes, bad judgment’) to neutralise the merciless mockery that Hague subjected him to.

Boris Johnson seems to have pushed PMQs further down his priority list than even Blair ever dared and that is starting to become a problem. A clue to the casual attitude towards this weekly parliamentary event taken by the PM lies in the fact that he does not even amble into the chamber until it is called. Keir Starmer, by contrast, is already in place and is seen to listen carefully to the end of the departmental question time that precedes it.

Of the two men, it is clearly Starmer who knows this is an important weekly moment and has war-gamed the course of exchanges in advance. Johnson, meanwhile, gives credence to those hostile voices that claim his whole premiership is based on busking it, by attempting to busk it.

Maybe it is because he is so immersed in steering the ship of state through the huge crisis of coronavirus that PMQs has simply dropped off his radar as a potentially perilous or fraught event. Or perhaps he believes that in a socially-distanced chamber containing just a few dozen MPs, the event no longer matters. But in fact, being deprived of a chorus-line to cheer him along and barrack the opposition leader makes it more dangerous for him rather than less.

This week Starmer was able to do the job on Boris that Andrew Neil never got a chance to during the election campaign, by politely yet forensically pulling him apart. The particular point at issue was how Covid-19 got into care homes and Johnson was left trying to deny what official guidance had said in black and white.

Neither did the PM have a convincing answer ready to a question about why Downing Street had dropped the Covid international comparisons chart from its daily briefings. Yet it should have been obvious that Starmer would ask this and equally there was a perfectly serviceable response that could have been given: the UK fatality numbers now count deaths in all settings while most other nations do not and therefore like-for-like comparisons can no longer be made.

Worse still, for the second week in a row Johnson appeared to have no shots in his own locker – nothing at all with which to counter-attack Starmer. Given that the format of PMQs – giving him six goes at the PM in a ghost ship Commons – so obviously suits Starmer’s courtroom skill set, this is simply not good enough.

While the Leader of the Opposition is obviously a big upgrade on his predecessor, the electorate and the commentariat need reminding as often as possible that his party remains a rabble, populated by bores and low grade blowhards who must never be allowed anywhere near the levers of power.

So where is Johnson’s counter-attack dossier, full of idiotic quotes from the likes of Richard Burgon and Dawn Butler? Just two hours before today’s PMQs, Butler had claimed that the PM was ‘sending people out to catch the virus’. Such comments could have been used to puncture Starmer’s claim to lead a patriotic and responsible opposition.

A Tory counter-attack team should be preparing reams of this stuff each week, highlighting the worst excesses of Labour lunacy. It should also be including various gentler – but still cutting – lines to use at Starmer’s direct expense. His habit of claiming Government decisions, such as the very idea of publishing a plan about how to move out of lockdown, have been forced by his own previous recommendations is surely ripe for some mild ridiculing.

It may be that Johnson would choose not to use such counter-attack lines, should his exchanges with Starmer be running smoothly or should he decide they would risk looking unstatesmanlike. But simply not having any shots ready to throw at times when he is on the ropes is plain sloppy.

Performance at PMQs has never been the central determinant of electoral success or even of party leader approval ratings. It still isn’t. But it is a significant contributory factor. As some of those soldiers who helped to get the Nightingale Hospitals up and running at lightning speed could no doubt have informed the PM: proper preparation prevents particularly poor performance.