Selby byelection shows the Conservative Party no longer knows what it should stand for - Justine Greening

In Somerton and Frome, a 19,000 Parliamentary majority disappeared as long-standing, rural Conservative supporters haemorrhaged to the Liberal Democrats. Meanwhile, in Uxbridge and South Ruislip, a solid Conservative seat since 1970, an 8,000 majority was nearly, but not quite, obliterated, saved only by voters’ desire to give London Mayor Sadiq Khan a slap in the face for his poor handling of the introduction of the Ultra Low Emission Zone.

But of the three by-elections taking place last Thursday, the Selby and Ainsty one was by far the most significant. With its mix of traditional rural Conservative voters and new red wall-style Northern voters, it arguably represented Boris Johnson’s 2019 General Election landslide majority rolled into one constituency. But Boris Johnson has gone from Downing Street and Parliament. And it may well be that his voter base has gone too.

A 24 per cent swing turned 20,000 Conservative majority into a 4,000 Labour majority - a staggering by-election outcome by any measure.

It represents a potentially huge problem for the Conservatives. Under Mr Johnson, they bet big on a unique new voter coalition of Red Wall and traditional Conservative voters - just like those in Selby and Ainsty - brought together by getting Brexit done and levelling up. It’s a bet that paid off in 2019 when Jeremy Corbyn made the Labour Party so unelectable that many of those voters felt they had nowhere else to go. But whether you like his politics or not, Sir Kier Starmer has made his Labour Party possible to vote for again. Electors feel they have a choice of not voting Conservative, either via Labour or the Liberal Democrats, and they are taking it in droves.

It should hugely concern Conservative Party strategists if the Party’s 2019 unique voter coalition turns out to have been a temporary, one General Election phenomenon. What then?

What if, to analogise, traditional wealthier Conservative core voters and red wall voters turn out to be like a couple that meet in a nightclub, hit it off on one evening but wake up in the morning to discover that other than being in the same place at the same time the night before they’ve not much else in common.

The uniting factor was perhaps ‘getting Brexit done’ but as time passes, the common ground is now falling away. What is the political strategy for the future that holds it together?

And it’s a bet that came with an explicit cost for the Conservatives. The party steadily turned its back on other voters - younger voters, urban and metropolitan voters, graduates, and Remainer - often Southern - voters.

It is left with a disillusioned 2019 voter base, wondering if there was ever really a plan on either Brexit or levelling up. And, there is a wider voter base which feels the Conservative Party is not interested in it and with other choices at the ballot box.

It will take much more than a reshuffle by Prime Minister Rishi Sunak later in the year to find answers to the questions these by-election results collectively pose. If the 2019 Conservative voter coalition has lost faith with it, then what else - and who else - is today’s Conservative Party for?

Talking with former Parliamentary colleagues, there is a sense that the party is drifting. It seems there are now simply too many factions within the Parliamentary Party with widely divergent views on what kind of Britain they want to see in the future.

And the political road ahead gets harder still. Aside from facing two more difficult by-elections in Mid-Bedfordshire and Tamworth constituencies later this year, next year it will have to fight a General Election manifesto on all 650 seats. It is hard to see the many factions within the party being able to easily agree on a party manifesto, let alone show the disciplined and unified front needed to successfully campaign on it. This week’s by-election results are much more than government midterm blues, or the results of 13 years in power and an electorate simply feeling like it wants a change. They hint at a more existential challenge for a present-day Conservative Party that too often comes across as if it collectively no longer knows what it should stand for.

There is a sense that its tendency towards culture war politics has alienated whole swathes of voters. And in the meantime, this has fatally combined with a lack of delivery of demonstrable benefits from either Brexit or the levelling up agenda that led so many Red Wall Conservatives voters to give the party a chance for the first time.

So the Conservative Party has somehow lost its moorings and its sense of how to drive real, long term change for millions of people.

If that is the case, then Thursday’s by-election results and the party potentially going into Opposition at next year’s General Election are only the beginning of today’s Conservative Party’s problems.

Justine Greening, who was born and raised in Rotherham, is a former Secretary of State for Education.