Two years ago today, Jeremy Corbyn launched something of a fashion bombshell: a bespoke suit with the words “For the many, not the few” stitched into it in red pinstripe.

It was exactly a week before the general election, and the then-Labour leader was on the campaign trail in Whitby, home of Dracula, Captain Cook and, it turns out, thousands of Conservative voters — apparently unmoved by Mr Corbyn’s sartorial flair, they declined his entreaty to ditch Robert Goodwill, their MP since 2005.

That Labour was dreaming of capturing a moderately safe Tory seat, held at the time by Mr Goodwill by nearly 4,000 votes, seven days out from polling day gives an indication of how badly party strategists had misread the mood of the electorate. That night, the sitting MP extended his majority by more than 10,000, and “Red Wall” seats to the north and west of Whitby, which Labour had taken for granted for decades, toppled to Boris Johnson’s Conservatives.

Two years on, what can we learn from a general election that today, given all that has happened since, seems like another age; as historic and irrelevant as the Three Day Week, or Suez Crisis?

It may feel like ancient history, but close examination of the events leading up to the 2019 general election suggests there are indeed lessons to be taken — and not just that to pay attention when a strange new flu emerges in a Chinese city few of us have heard of.

Last week, the latest in the political geeks’ bible the British General Election series was published; multi-authored by Robert Ford, Tim Bale, Will Jennings and Paula Surridge, it contains some fascinating insights into the factors which stunned Mr Corbyn’s Labour Party by bringing Mr Johnson his unexpected 80-seat majority.

Dotted through its 659 pages are both encouragement and warnings for the Prime Minister as he contemplates how to repeat the trick in the future. 

The accepted wisdom that Boris won because of Brexit, and specifically the power of the slogan “Get Brexit Done,” does appear to be borne out by the psephology. Yet there is evidence to suggest these votes may prove transient; the reason the Red Wall fell to the Conservatives wasn’t down to a mass conversion to Tory ideology, but because Vote Leave was stronger in the north than elsewhere. With Brexit indeed now Done, might those votes prove leant rather than permanently gifted?

Far from reaching parts of the electorate other Tories cannot, as we are often told of Mr Johnson, the numbers show he actually fared worse two years ago in terms of Conservative vote share than Theresa May did while losing her majority in 2017. 

The difference was the collapse in the Labour vote in 2019. Mr Corbyn and his pinstriped suit clearly failed to charm voters as he had when he came up against Mrs May in 2017.

Minus Mr Corbyn and Brexit, and having gone through the shattering experience of coronavirus, will Mr Johnson remain in Number 10 after the next election?

The slump in the Labour vote shows how crucial the role of Leader of the Opposition will be to answering that question. Sir Keir Starmer is clearly a different beast to Mr Corbyn, but that does not mean he will necessarily fare any better against Mr Johnson. Indeed, the shadow cabinet reshuffle he has just performed, with recalls and promotions for the likes of Yvette Cooper, David Lammy and John Healey, gives the Prime Minister a golden opportunity to paint the current Labour leader as Ed Miliband Mark Two. And look how that went for Labour in 2015.

The trouble is, to achieve that, Mr Johnson needs to be at least as plausible compared to Sir Keir as David Cameron was when he went up against Mr Miliband and his Ed Stone.

Too many own goals such as the Downing Street Christmas party, with its overtones of One Rule for Them-ism, or a particularly brutal post-mortem from a Covid-19 enquiry, and it may not be Mr Cameron in 2015 that the PM comes to emulate, but a floundering, scandal-tarnished, aging Gordon Brown in 2010.

Rosa Prince is Editor of The House