Boris Johnson enters the third year of his premiership in a much weaker position than when he started it. Alongside major rebellions inside his own party, humiliating by-election defeats and growing speculation across Westminster about who will succeed him, he has another problem: the coalition of voters who propelled him into Number 10 Downing Street is now rapidly falling apart.

One reason why Johnson emerged with the biggest Conservative majority since Margaret Thatcher’s third and final majority in 1987 is because he united Leavers; those who have felt ignored, neglected and even held in contempt by much of the ruling class.

While this process began under Theresa May, Johnson’s ‘Get Brexit Done’ strategy took it to its logical conclusion. He recruited more than three-quarters of Leavers (and a not insignificant one-quarter of Remainers) in 2019 and cannibalised much of Nigel Farage’s vote along the way. And, at least until this autumn, he managed to retain the support of almost all of these voters, aided by a strong vaccine programme.

These voters also changed the nature of conservatism, something Johnson’s advisors have clearly struggled to recognise and respond to. The Conservative party today is simply far more dependent on people who want strong borders, controlled and ideally less immigration, who want the government to prioritise national (not universal) rights, a more robust response to radical left progressives and for serious reforms to the progressive consensus that has dominated Britain and many of its institutions for 20 years. Their number means they will also influence the outcome of any future leadership election: no aspiring leader can win without them.

But today this coalition is fragmenting. Over the past six months alone, the share of Leavers loyal to Boris Johnson has crashed by almost 20 points. Almost one-third of his 2019 electorate now say they will not vote at the next election, do not know who to vote for, or refuse to say who they will support. While a growing number are switching to Reform, after being angered by Covid restrictions and a ballooning state, most of the people abandoning Boris Johnson are not switching to Labour or another party; they are simply giving up on politics altogether. Many are drifting into apathy, as they did before Brexit and before they believed, briefly, that Boris Johnson was the radical alternative they craved. Can he win them back? That is his primary challenge in 2022.

Unless he does, then the local elections in May will throw further light on these defections and pile yet more pressure on the Prime Minister. Crucially, these elections will not only be held across London but in more than 30 metropolitan boroughs, from Barnsley to Bolton, Dudley to Walsall.

Many are not only scattered across the Red Wall but what I call the Red Wall 2.0, where Labour majorities now hang by a thread as a result of Theresa May’s and Boris Johnson’s successful incursions in 2017 and 2019. Today, there are nearly 30 seats in the Red Wall 2.0 which have Labour majorities of fewer than 4,000 votes. The message of the last election was that Johnson can offset losses in southern Remainia if he leans into this political realignment. But does he want to?

Labour will head into these elections and 2022 looking for signs of recovery outside of cities and university towns while Johnson’s critics will be looking for further evidence that his appeal is on the wane. And on the wane it is. In the polls this month Johnson’s leadership ratings crashedto a new low of minus 29 (Starmer is on minus 8) while his government’s competency rating collapsed to minus 30. Ask people who would make best Prime Minister and six months ago Johnson led Starmer by 11 points; today, Starmer leads Johnson by one. More people now think Starmer not Johnson is most likely to stand up for the interests of the United Kingdom.

Amid a levelling-up strategy that is still AWOL more than two years into Johnson’s premiership – and amid growing concerns among cultural conservatives about illegal immigration, Covid restrictions and what many see as an intensifying culture war being waged against British history, identity and culture – it is not hard to see how these local elections become more significant than those in the past. If Johnson no longer looks like a leader who can retain support in the Red Wall, and is already haemorrhaging support in historic Tory heartlands such as North Shropshire, then it is not hard to see how the case against him goes from being speculative to watertight.

It is not yet the end of the road for Boris Johnson. He is routinely underestimated by much of SW1 and many of the fundamentals remain in his favour, even if his premiership remains in disarray. His electorate is still distributed across the country far more efficiently than Labour’s. The left has not yet demonstrated a serious recovery at actual elections (Labour’s vote fell by 12 points in North Shropshire). And Labour is still stacking votes in its strongholds while losing votes in areas where it needs them.

Johnson’s strength across England also bodes well for a future Conservative campaign that will inevitably focus on the threat of a Labour-SNP coalition. The absence of the Brexit party will also help (recent research suggests Johnson’s majority in 2019 would have extended to more than 100 if Farage’s candidates did not stand). It is not yet the end of the road. But unless the Prime Minister and his team can successfully navigate these tests, then it may well be the beginning of the end.