Most of the Kippers, including Farage, were originally Powellite/Thatcherite conservatives. In 2010, when Cameron got into bed with Nick Clegg , the traditional hard Right wing of the Tory party was horrified and some shifted to UKIP. Their unique selling proposition policy was, of course, extreme Euroscepticism.
As with Enoch Powell right wing Tories, now in UKIP or contemplating it, linked anti-Europeanism with a toxic mix of xenophobia and anti Immigration, Islamaphobia and flag-waving nationalism. In 2014 this mix won UKIP the European elections.
David Cameron responded to the threat from the Right in two ways. Firstly, with Lynton Crosby’s help, he destroyed the LibDems in the 2015 General Election. Second he promised a referendum on EU membership. Both actions shifted the Conservative Party in the direction of their hard core dissidents and of their UKIP deserters.
The 2016 referendum win, financed and substantially organised by the extra-Conservative Right, eventually led to Boris Johnson’s rise to power and to the destruction of One Nation Conservatism which a few short years earlier had been the mainstream and in power. Johnson was not seen by the Right as “One of Us” – it was quite clear that he wasn’t one of anybody, except himself. But he was seen as a potential election winner. Rightly as it turned out.
The Kipper mindset had always been economically free enterprise and small state favouring. The Cameron/Osborne austerity policies had recognised the attraction of Thatcherite neoliberalism to many Tory MPs and voters. Boris Johnson is ideology free and is a populist. But around him are Ministers, including the Chancellor, who are not!
Having defeated Cameron over Europe the overwhelmingly Hard Right (economically) senior ministers (Sunak, Raab, Truss, Patel and the rest) may well feel emboldened to try and rein Johnson in over public expenditure and higher taxes. They declared their intent some years ago in “Britannia Unchained” .They are flexing their muscles.