When the election campaign finally ends, the defining moment will almost certainly be the calamitous decision taken by Rishi Sunak to leave the D-Day commemorations in France early.

It is not so much the decision itself but the backdrop against which it was announced; namely that the PM was returning early to do a one-to-one election interview with ITV.

Among the many reasons there could have been for cutting out early, this was not exactly a priority - although somehow the Prime Minister’s office seemed to think it was. Imagine if there had been a focus group testing the idea; it would have drawn universal disapproval.

The PM at least realised what a dreadful decision it was but too late to scrap it, and the multiple apologies were unconvincing; especially when he appealed for the other parties not to politicise the saga.

It left many wondering exactly what advice he was getting from his political advisers and spin doctors. “Well, we’ll cut out of the D-Day event because we’ve got to record an interview” didn’t appear to ring alarm bells until it was too late.

The withering and unrelenting criticism could not be halted and left some wondering why he could not sack anyone, for which the answer was that the PM realised it would still come back to him.

Of course the election roadshow moves on - which may be some relief for the Conservatives - but the catastrophic blunder leaves an indelible stain on the Prime Minister, who in boxing terms is on the ropes if not yet on the canvas.

You can tell how parlous his position is that some commentators have advocated switching leader mid-campaign.

Improbable though it is, the very idea is just another sign that the Conservatives are on the back foot and are running out of time to reverse their fortunes.

• According to snap polls on the seven-strong TV hustings, the debate saw approval ratings highest for Nigel Farage, who in an official survey of more than 1,000 people received 25% support.

At times, the debate looked like it was turning into two separate hustings - one between Penny Mordaunt and Angela Rayner and another involving the remaining five panellists.

It was marginally better than the head-to-head between Sunak and Starmer - but that’s not saying much.