Where have Boris Johnson’s diaries and WhatsApp messages gone? The row over the demands of the Covid Inquiry for evidence from the former prime minister and his aide Henry Cook took another twist yesterday, with his team insisting that he has already handed over all the relevant material to the Cabinet Office and that it is in fact the government that’s holding the whole thing up.

The inquiry wants all messages from Johnson’s phone, and had demanded them by 12 May, then 4 p.m. yesterday, and now there’s another deadline extension of 1 June. The Cabinet Office had disagreed with the extent of these requests, saying not all of it was relevant and that revealing all the communications from the pandemic now, rather than under the 30-year rule would damage the decision-making process in government more widely. It is worth pointing out, though, that the inquiry doesn’t need to publish everything it is handed.

A lot of this fight is about the bad feeling between the Johnson camp and Rishi Sunak

Already the Johnson camp has been fighting with the Cabinet Office over the way it handled new information that was passed to the police about potential rule-breaking. Yesterday, the accusation was that the hold-up with the messages wasn’t Johnson being recalcitrant, but the government. The Cabinet Office then accepted, just before the deadline passed, that it didn’t have the material. So where is it?

Labour has got in on the act, with Angela Rayner saying ‘it now appears that vital evidence has gone missing’ and ‘must be found and handed over as requested if the whiff of a cover-up is to be avoided and bereaved families are to get the answers they deserve’.

A lot of this fight is about the bad feeling between the Johnson camp and Rishi Sunak, as well as bits of the wider government, about the way he left office last summer. But there is also a wider question about the inquiry and its efficacy and importance.

Publishing messages ahead of the 30-year rule might have an impact on decision-making, but will the inquiry have a real impact on decision-making more widely? The Chilcot Inquiry into the Iraq War took so long that successive governments had managed to repeat many of the mistakes it highlighted, while key figures had exited the political arena and didn’t have to account for their decision-making in the same way as those still in government.

It is far more likely that the messages disappear into a vortex for a long time than it is they have any real impact on how government works – though one might hope the government could work well enough to find out where they’ve gone.