For anyone who has ever suffered from impostor syndrome, Rishi Sunak’s election campaign is a kind of therapy. No matter how underqualified you might feel for a task, there is no prospect of exposure as brutal as that now inflicted on the prime minister. He looks shaken, but will no doubt recover his composure soon enough. Sunak will arrive at the conclusion reached by Liz Truss and Boris Johnson before him: that the only failure was of other people’s loyalty and nerve. Taking responsibility for defeat is alien to the Conservative culture of automatic right to rule. It runs deep, insulating a leader’s ego from evidence of their inadequacy. The idea that Britain is, at heart, a Tory country has rubbed off on Labour. A record of defeat will do that. Rejection by the electorate has been so deeply internalised that even now, when victory looks certain, there is a lingering horror of complacency. In marginal seats that are certain to flip red, candidates are drilled to say “if” and not “when”. Wariness of believing the polls is understandable given how deep a hole Labour was in after the last election. Recovery in a single term looked ambitious. A landslide win was out of the question. For most of the past four years, the focus in Keir Starmer’s office has been on restoring basic competitiveness. That has mostly been a matter of party management, taking control of the machine, imposing an iron grip on candidate selections, ferocious message discipline, purging acolytes of Jeremy Corbyn and scouring his name from the Labour brand. Getting the party fit to win an election was a gruelling and time-consuming operation that has not left much bandwidth for the question of what to do after victory. Most of the strategic thinking has been defensive: what not to say on tax and spending plans; how to shut down talk of Brexit and other traps to swerve. Caution will be the watermark on every page in the manifesto launched today. Partly that expresses recognition of public mistrust. Voters have become wary of pyrotechnic pledges that fizzle out too fast. Starmer intends to under-promise in the hope of pleasantly surprising a sceptical electorate with over-delivery. The timing of the election was also a factor. Labour was all poised for the combat side of a campaign. Fingers had been hovering over the send button on digital ads for months. (By contrast, Tory candidates felt ambushed by their own leader’s surprise attack.) But the side of the Starmer operation that is dedicated to planning for office needed more time. It hasn’t helped that the two functions – capturing power and using it; swords and ploughshares – have been working as separate silos, commanded by the leader’s two most powerful aides. Securing the win has been the task of Morgan McSweeney, Starmer’s campaign director. The job of preparing for government belongs to Sue Gray, the Labour leader’s chief of staff. McSweeney is a ruthless operator within the labyrinthine, faction-riven world of Labour machine politics – a milieu for which Starmer had little intuition when first elected to the leadership. His comfort zone is closer to the upper echelons of the civil service, from where he recruited Gray. She has a keen sense of the gap between what opposition MPs think of as developed policy and something that might actually withstand the stress-test of implementation. But Gray only started work last September, at which point not much policy homework had even been done, let alone completed to the requisite standard. The Gray and McSweeney roles complement each other, but there is also an inherent tension. A campaign founded in avoidance of committing to policy retards the business of getting policy right. For shadow ministers and advisers, most of whom have no experience of government, a fierce prohibition on talking about awkward choices is a powerful incentive not to think about them. Combine that with a dread of taking the outcome of the election for granted and it can be hard to sustain a focus on life after victory. Gray’s mission to plan how things will work when Labour wins can feel like a second-order priority in a cult of always saying if. One corrective to that tendency is the “access talks” between shadow ministers and civil servants that are supposed to prepare both sides for possible regime change. This has been Gray’s responsibility. By convention, the process needs permission from the incumbent prime minister to get under way. Sunak only pushed the button in January. Reports from inside Whitehall say progress since then has been patchy. That is partly a problem of sequencing and centralised control – a high volume of talks needing signoff from the leader’s office. But there is also muttering from inside and outside the Labour camp about shadow cabinet teams being too narrowly focused on campaign craft. There is a suspicion of naivety about the challenges of working in a department, the tricky balance between deference to civil service expertise and the need for assertiveness in driving a political agenda to fruition. Few in the Starmer project have experienced the ferocity of life in government. Those who have fret about callowness in some colleagues. As one old-timer said to me recently: “They all think they are working incredibly hard now, that this is how intense it gets. They have no idea what’s about to hit them.” When it comes to the administrative side of government, Starmer is better qualified than most opposition leaders. As a former director of public prosecutions he has actually run a large department. Those who have worked with him say he will slot into the implementation and management side of being prime minister more intuitively than he took to the showmanship and raw pugilism expected of an opposition leader. But one role does not replace the other. Campaign politics doesn’t make way for judicious policymaking. They merge in a frenzy. The McSweeney and Gray modes of Starmerism have to somehow become one joined-up Downing Street operation. It isn’t at all clear how that is going to work. The challenge of maintaining discipline in opposition will look tame once MPs, used to scoring points against a failing government, find themselves on the receiving end, feeling the heat of blame for incumbency. Old rivalries will resurface, while new rifts open between cabinet ministers warring over scarce resources from a parsimonious Treasury. The pace at which hard choices fly at a prime minister demands agility and clarity of direction so people outside the innermost circle have confidence to take their own decisions, anticipating the will of the leader. Starmer might yet display those qualities in No 10. It hasn’t been his signature style so far. Every former prime minister says there is no preparation for the intensity of a transition that happens within hours of votes being counted. No opposition arrives ready to govern and it is much, much harder than it looks. One advantage Starmer will have is coming after a parade of disastrous Tory leaders. A modest display of competence will be flattered by comparison with what came before. Another strength, and a contrast with Sunak, is the humility, cultivated in exile from power, that treats high office as a rare privilege, not an automatic entitlement. Rafael Behr is a Guardian columnist