Boris Johnson won't commit to resigning if Brexit is delayed...

Jeremy Hunt hit the frontrunner with his gotcha question early, during the first of many shouty exchanges on Brexit. Would he resign if he did not deliver Brexit by 31 October?

Perhaps unsurprisingly for a man who has spent a lifetime coveting the keys to 10 Downing Street, Johnson would not be drawn – which rather undermined his "do-or-die" commitment, repeated on stage, to leaving by the deadline at any cost. Hunt argued that his opponent's promise was unattainable.

His critics in the Conservative parliamentary party – and, indeed, the many opponents of a no-deal Brexit who have somehow wound up supporting his candidacy – believe that prevarication is a sign that, when push comes to shove, he could be more flexible than his rhetoric implies.

...and he's anticipating an election anyway

Subjecting anything Johnson says to close textual analysis is a risky business. But among his most striking utterances this evening was his description of a general election as "forthcoming".

Given that his revealing turn of phrase came in reply to a question about whether parliament's opposition to no-deal meant a snap poll was inevitable – and was followed by a promise to make the case for a "modern Conservatism" to the country – it appears that Johnson is planning to go to the country earlier than 2022, voluntarily or otherwise.

The prorogation of parliament is looking more likely

Challenged to rule out suspending parliament as a means of ensuring Brexit happened on 31 October, Hunt and Johnson gave the answers we would expect.

The foreign secretary ruled it out, joking that it was not what he thought "taking back control" looked like. Predictably, his predecessor took the opposite view – insisting that no mechanism for delivering Brexit be taken off the table.

Back in Westminster, Johnson's team have taken heart from the defeat of Dominic Grieve's bid to legally bind parliament to sit throughout September and October, regardless of any attempt to adjourn or prorogue it. Despite being dismissed by every leadership candidate bar Dominic Raab early on in the contest, the nuclear option is back on Johnson's agenda.

Evasion is Boris Johnson's biggest weakness

Hunt was at his strongest – and his opponent at his least convincing – when he demanded a straight answer from Johnson and did not receive one: most significantly on his personal commitment to the 31 October deadline, Heathrow, and Donald Trump's criticism of Theresa May and Kim Darroch.

He went as far as to accuse him as not answering a single one of his questions, which, despite not being strictly true, speaks to one the main misgivings Tories have about Johnson – that he is not being entirely straight on the issues that will define his premiership.

That aversion to giving a categorical answer could yet fracture his parliamentary coalition.

The Conservatives won't be winning back social liberals anytime soon...

Quite apart from his enthusiastic support for the hardest and most divisive form of Brexit, Johnson's refusal to condemn Donald Trump in anything more than mealy-mouthed and equivocal terms served to illustrate an unpalatable electoral truth: that he is in no place to appeal to Remainers, or stem the tide of suburban losses to the Lib Dems (both claims his more optimistic supporters make).

If there was ever a pitch designed to repel those sorts of voters, it's defending the US president – or at least being seen to. His gamble is that his hard line on Brexit wins enough voters of the opposite persuasion – Leavers in the Ashfields and Bishop Aucklands of the world.

...and Jeremy Hunt, however punchy, is doomed

The foreign secretary gave a spirited, combative performance, and Johnson spent much of the hour on the ropes and visibly rattled as a result.

But does it stand any chance of translating into a shock victory? For the answer, look to Johnson's reply to the final question of the debate: what qualities did the candidates most admire in their opponent?

The frontrunner responded with mockery of Hunt's ability to change his mind on Brexit. Add that to his willingness to commit what many Tory members believe to be the unforgivable heresy of entertaining EU membership beyond 31 October and it is plain to see why, despite his far from watertight platform, Johnson remains in pole position.