And with one bound, Theresa May is, well, not free exactly. But certainly at liberty to leave the frying pan for the next blazing inferno. The prime minister has survived talk of a leadership challenge in much the way she usually does, which is less by pulling off some dramatic intervention (for all the talk of her “emotional and personal” address to the 1922 Committee, MPs coming out of it didn’t seem able to recall a single memorable line) than by letting them have a good hard think about the alternative.

People will tolerate a surprising amount when all the other options look dreadful, which is fast becoming the guiding principle of May’s government. But while her modus operandi of grinding opponents down into a state of weary resignation still works reasonably well within her own party, it won’t help with her next challenge, which is delivering on a promise earlier this month to end austerity. Here is the real litmus test of what the Tories actually learned from their 2017 election disaster, and whether they’re capable of doing anything with that knowledge.

May’s speech to the party conference already feels like a lifetime (and several leadership crises) ago, easy to forget in all the ensuing melodrama. But on Monday her chancellor must deliver a budget that will now be judged almost solely on whether it fulfils that conference promise – or it will if Labour has anything to do with it, which is why the shadow chancellor, John McDonnell, is so eager to offer his own definition of what ending austerity really means.

Say the A-word, and most people probably think about food banks and rough sleepers, headteachers sending home begging letters asking for cash, or the home affairs select committee saying that underfunded police forces risk becoming almost an “irrelevance” in some areas.

John McDonnell says Labour will reverse cuts and 'end austerity' Read more

Its meaning is now as much emotional as technical, shorthand for a general feeling of things coming apart at the seams – some of which genuinely is due to budget cuts and some of which has more to do with bad decisions. Universal credit has quite understandably come to symbolise everything that’s gone wrong in the past eight years, and it was austerity that carved billions out of Iain Duncan Smith’s original plan to simplify the benefits system, turning it into a cover for smuggling through welfare cuts. But it is the delays and errors and clumsy assumptions built into the system that so often push people into debt in the first place, which means sorting out the mess probably requires both cash and a rethink of how it operates.

And what most people expect from the words “ending austerity” goes well beyond the strict economic definition of easing off from cutting the deficit. It’s a general feeling that the sun might finally be coming out again; that their own lives are getting easier; that they no longer see so many sleeping bags in high street doorways; perhaps even that the government accepts it might have gone too far and is genuinely ready to change tack. For without the latter, Hammond could end austerity in the strict economic sense yet barely touch the sides of the political disaffection it’s caused. A technocrat’s budget that grudgingly keeps to the letter, but not what voters surely hoped would be the spirit, of May’s promise would be almost worse than no promise at all.

It goes almost without saying that if the Brexit talks collapse, then all Hammond’s efforts are for the birds; no chancellor can conjure up a cheery feelgood mood while sick people are stockpiling medicines for fear of running out, or civil servants are talking of chartering ships to bring food aid to Britain. But in the near-miraculous event that Brexit doesn’t go horribly wrong, and even assuming that revised forecasts from the Office for Budget Responsibility give him a bit of room for generosity, the Tories still have a reckoning with the electorate ahead.

Here is the real litmus test of what the Tories learned from losing the 2017 election, and whether they’re capable of doing anything with that knowledge

For the overriding impression left by that party conference was that most Tories still don’t get exactly why they so nearly lost the last election. Fringe meetings were jam-packed with grassroots members earnestly trying to understand why young people seemingly don’t want to vote for them. But even among those who grasped the peculiar meaning of “young” in this electoral context (not so much Generation Z as people in their 30s and early 40s, with jobs and kids and often mortgages, living in marginal seats) there’s often a curious blind spot.

It’s comforting for Tories to blame their unpopularity on the fact that fewer people are becoming homeowners, since that fits with a very conservative idea about the virtues of living in a property-owning democracy. But as important as housing is, it’s very far from being the only problem (school funding cuts are right up there for many of May’s target voters) and it’s not what has retoxified the brand. The damage done not just to their own life prospects but to the social fabric over the past eight years is surely a large part of what has made voting Conservative toxic by association for so many.

May hinted rather opaquely at that in her conference speech, saying that the process of getting the deficit down had been “painful”. But if she wants those millennial swing voters back now, she’s arguably going to have to do more than ease off on austerity and hope they obligingly forget it ever happened. She’s going to have to apologise for it, or at the very least acknowledge the damage done, if she genuinely wants people to think it’s over. And in that sense, this budget isn’t really the end of austerity. It’s barely even the end of the beginning.

• Gaby Hinsliff is a Guardian columnist