Even as Chris Huhne, whose actress mother voiced the Speaking Clock, waits to hear what the time – sponsored by Accurist – will be, David Cameron (pictured) prepares to visit his vacated seat of Eastleigh later this week. This is most unusual. Whatever the psychological import of this campaign for both Coalition partners, the convention that PMs are too grand for by-election campaigning is such an old and powerful one that we must look elsewhere for an explanation. And having looked, we find that this is the Hampshire town where the young Benny Hill was a milkman.

It was this early career which inspired his 1971 Christmas No 1 “Ernie (The Fastest Milkman In The West)”. In 2006, on including the poignant ballad about Ernie’s fatal battle for the widowed Sue with love rival Two Ton Ted from Teddington in his Desert Island discs, Mr Cameron, pictured, revealed that it was the only song of which he knew every single word. His trip to Eastleigh must be analysed not as a high-risk political manoeuvre, then, but as a pilgrimage.

Seven years ago, Mr Cameron coyly declined Sue Lawley’s request for a rendition. But that was then, and now we must stand for the unusual vista of a florid-faced chap with a blue rosette regaling startled shoppers with “Now Ernie loved a widow, a lady known as Sue/ She lived all alone in Liddley Lane at number 22/ They said she was too good for him, she was haughty, proud and chic/ But Ernie got his cocoa there three times every week.”

Political manoeuvring to novelty songs

Mr Cameron is not the first Tory leader to plump for a novelty hit on Desert Island Discs – Mrs Thatcher, who as the one-time milk snatcher could hardly risk Ernie, picked Rolf Harris’s “Two Little Boys” – and he probably won’t be the last.

Paddy Power goes 2-7 that, when he makes a second appearance after ousting his Buller chum, Boris Johnson will choose Chuck Berry’s “My Ding-A-Ling” (“My ding-a-ling, I want you to play with my ding-a-ling”). As with the incumbent and Ernie, he knows all the words.

Time for a cup of  hot sweet tea

Concerns for the mental wellbeing of Chris Grayling, the Injustice Secretary, mount alarmingly. Last week we considered Chris’s befuddlement over gay matters as he pledged to separate gay prisoners two days before he voted to legalise gay marriage. Now he seems even less sure whether he’s Chemical Ali or Chemical Sally over sentencing. A week ago, the Mail on Sunday quoted him pledging to stop violent criminals being let off with cautions. On Tuesday he told the Commons that, in cases where alleged victims refuse to give evidence, he is considering letting rapists off with a caution. He needs to get his act together urgently, before someone sits him down with a cup of sweet tea and ask him if he can name the current Prime Minister.

Real life measles  scare for the Mail

The Daily Mail’s anguish about the rise in measles cases among teenagers who were not immunised as babies brings to mind the comic Emo Philips’s reply when a German girlfriend moaned about the dearth of decent bagels in Berlin. And who’s fault is that? In an unwonted show of arrogance, the Mail refuses to apologise for its campaign proselytising the fictional link between the MMR triple jab and autism. Nor has Melanie Phillips, who led the charge with a plethora of articles, one gem of misinformation being headlined “The Truth”. If only Mad Mel had had some newspaper precedent to warn her of the boomerang dangers inherent in that one.

A sorry affair for quiz contestant

Hats off to Steve, a contestant on ITV1’s glorious teatime quiz The Chase. “What is the name of John Major’s wife?” asked host Bradley Walsh on Friday. “Edwina,” said Steve. Soooo close.