The painful truth for Tories is the outstanding leadership candidate remains David Cameron

Shortly after David Cameron stepped down as prime minister, but while he was still the MP for Witney, he went for dinner with some of his biggest supporters on the back benches. These were MPs with marginal seats who had – and still have – a great deal of affection for the man they credit with getting them elected in 2010 and re-elected, mostly with increased majorities, in 2015.

The conversation turned to the question of his replacement at the top of the party. Cameron mused that he and Theresa May had worked together since 2001. They had served in the shadow cabinet and the cabinet together. They had been on the same side of every major political battle, inside and outside the Conservative Party, for more than a decade. But, Cameron realised, “I don’t know a thing about her.” They had never gone for dinner or had a prolonged conversation about the world outside of politics. Who was she?

One of the important subplots of the last general election was that David Cameron and his dinner companions had more in common with the average voter than they might have thought. Although most people knew who May was, they knew very little about her and had few, if any, firm opinions about their prime minister. They were still more uncertain about Jeremy Corbyn and knew even less about Tim Farron, the Liberal Democrat leader.

The contest was an opportunity for all three to introduce themselves to the public properly. For Farron and May, the result was a disaster that ended the leadership of the former and blighted the premiership of the latter. While May’s encounter with the electorate was pocked with misfortunes, one of the biggest involved fox hunting and her public pledge to bring it back in the event of a Conservative election win.

The hunting of foxes with hounds is an issue that many politicos find mystifying. Posts about the topic from Labour’s official Instagram consistently perform better even than those on wildly popular topics such as the National Health Service. Even in urban constituencies, the whisper of bringing it back is enough to send the size of Conservative MPs’ mailbags soaring. And, at the last election, some of the stories most shared on Facebook related not to Brexit, or to economics, but to animal welfare in general and fox hunting in particular.

Jeremy Hunt’s bid for the Tory leadership was never in particularly good health. According to YouGov, which has accurately predicted the outcome of every leadership contest since its foundation, Johnson started the campaign with a 48-point lead over Hunt. Nonetheless, Hunt’s announcement that he would bring back the hunting of foxes with hounds irritated many of his supporters, particularly those MPs in marginal seats who know how toxic it can be.

It solidified the impression that has been growing among Conservative MPs: that Hunt is not and never will be the real deal. Like May, he is an unknown quantity to most voters, and like May, he will not benefit from further exposure.

The appeal of Boris Johnson to Conservatives – including the majority of the backbench MPs who were loyal to Cameron and to May – is precisely that he is a known quantity. He has been tested in two campaigns for the London mayoralty and the Brexit referendum. Their voters know who he is and where he stands, particularly on the central question of Remain vs Leave.

But clarity is a double-edged sword. One Conservative veteran recently despaired that polls about Johnson reminded them of a familiar problem from the pre-Cameron days of the Conservative Party. Throughout the late 1990s and 2000s, any proposition, no matter how popular, became electorally toxic once voters were told that it was a Conservative proposal. Johnson, they said, had a different quality in focus groups: Leave voters warmed to a policy when it was endorsed by the former mayor, while Remainers became more strongly opposed.

The problem that Conservatives hope Johnson will solve is the emergence of a genuine four-party politics, with the Tories, Labour, the Liberal Democrats and the Brexit Party all on roughly a quarter of the vote; a combination that, once plugged into our antiquated electoral system, could see the Conservatives either swept to power in a landslide victory or wiped out. If a Johnson leadership works, it will be because he is able to reunify the forces of Leave without also doing the same to the massed ranks of Remainers.

Here, the Conservatives would come through the middle in many seats around the country and be back in for a fourth term. But the risk is that Johnson’s appeal to Leave voters is cancelled out by his toxicity to Remain ones: that the Conservative Party is defeated in Scotland by the SNP and in affluent parts of rural England by the Liberal Democrats, and is held to a draw in the small towns of England and Wales by Labour.

Jeremy Hunt’s advantage is that a policy doesn’t immediately become toxic to half the country when it is given his imprimatur. He is a blank canvas that voters could come to love, or, at the least, tolerate. Johnson is a Marmite figure and in choosing him Conservatives are taking a gamble.

Very few Tory MPs are unaware of that danger. But they think that they and their members are making the right choice in preferring the known risk of Johnson – a skilled political operator who is sharply polarising – to the uncertainty of Hunt, who is neither polarising nor particularly skilled. “Boris is a risk because of who he is,” one MP says. “Jeremy Hunt is a risk because of what he is.”

That choice may well be right. But it speaks to the biggest Conservative problem of all, that their outstanding candidate for the party leadership is still David Cameron, now permanently unavailable and, like Boris Johnson, contaminated by Brexit.