The defining promise of Labour’s general election campaign – the single word “change” – was modest and ambitious at the same time; easy to keep once, hard to keep on keeping. The simple fact of not being the Tories meets the most basic test of change. It also buys time while new ministers are excused for the dismal state of things that can’t reasonably be called their fault. How long? How far does the benefit of the doubt stretch before it snaps? This is not a measure of popularity, or not exclusively. Prime ministers face unpleasant decisions every day. Leaders who are serious about accountability should expect to be disliked much of the time. Unloved incumbents can reach the end of a parliamentary term looking like a safer bet than an opposition party mired in factional feuds and still blaming stupid, brainwashed voters for making the wrong choices. Keir Starmer cannot control how quickly the Tories get their act together, but he can deploy the amplifying power of his office to remind people why the old regime needed ousting, and manage expectations of how long it will take to fix the mess they left. A decade, at least, was the prime minister’s diagnosis, delivered ceremoniously from the Downing Street garden on Tuesday. The venue was picked as a visual aid to illustrate Starmer’s point. He indicated the spot where Boris Johnson’s staff were captured on film, partying when the rest of the country was in pandemic lockdown. Degenerate management at the top had rotted the economic and social foundations of the country, Starmer argued. Only once the Conservatives had been evicted was the full scale of their negligence revealed in budget black holes and broken public services. Things would get worse before they got better, Starmer warned, offering as a prize for endurance a more prosperous, fairer country somewhere over the horizon. By way of rebuttal, Conservatives struggle to defend their record. They rely instead on impugning the integrity of their successors. As evidence, they cite senior civil service appointments that have gone to figures with records of partisan allegiance to Labour and links to party donations. This is portrayed as an assault on Whitehall impartiality and a precipitous descent into cronyism. Downing Street insists that no rules have been broken and no protocols subverted. Aides will admit, privately, that days of hostile headlines on the topic are not ideal. But they are not overly anxious about Conservative newspapers whipping themselves into a frenzy of moral indignation over stories about a process that, even in the most jaundiced narration, can’t seriously be compared to Johnson-era scandals. Any suggestion of equivalence is damaging when voters are primed to think all politicians are cut from corrupted cloth. But no one is trusting the Tories or their media cheerleaders to adjudicate a contest of which party is more inclined to self-serving venality. A backlash over the decision of the chancellor, Rachel Reeves, to means test winter fuel payments looks like a more substantial problem. It threatens to put an early wobble in Starmer’s purposeful stride through tough financial choices. Alienating pensioners is always a perilous move and curtailing a universal entitlement was bound to foment anxiety among Labour MPs – a more awkward pool of dissent than the opposition benches for a government with a big majority. That legislative buffer is already down by seven after the suspension of rebels who backed an SNP amendment to the king’s speech demanding an end to the two-child benefit cap. Pushback on fiscal policy is a challenge of a different order to Westminster muttering about obscure personnel. With a budget in October and Whitehall departments preparing submissions for a wincingly tight spending review, there is rising tension behind the scenes as ministers plead for resources from the Treasury. There will be leaks and public rows when backchannels fail. Tuesday’s speech was a foretaste of how the prime minister intends to ride out such storms. He is betting on the public having greater reserves of understanding for the difficulty of the task ahead than they are credited with by MPs, left and right, who crave quick-fix solutions or pretend that pain can be swerved. Starmer’s confidence on this point is bolstered by his experience on the campaign trail, observing that audiences responded best to messages with the least bravado. He would get the most applause for admitting he had “no magic wand” to deal with the country’s ills. The Tory attachment to gimmicks, the conflation of policy and slogan, the flimsy manifesto, were not just unconvincing but actively insulted the intelligence of people who weren’t convinced. But there is no guarantee that voters who ostensibly give permission for unpalatable governing choices will then reward the leader who doles out meagre, bitter rations. In an age of entrenched scepticism about politics, there has to be a prompt downpayment of delivery before trust will be extended through whatever turbulence is to come. Here Starmer is caught in a catch-22. He must show some rapid improvement in the quality of government in order to be trusted with the task of making improvements that cannot be done rapidly. Recognising this conundrum is one reason for settling public sector pay disputes without fuss. It was wholly predictable that Conservatives would denounce the move as Labour falling into a routine of capitulation to its union paymasters, presaging a retro-1970s spiral into industrial strife. Absorbing that political attack, which resonates with a dwindling pool of people, was judged a price worth paying for the tangible benefit of having more commuters on the move and fewer hospital appointments cancelled. Ending strikes was one of very few immediately operable levers to pull with a direct effect of getting Britain working better under Labour. After that, it is all slower and harder. Starmer can remind people from time to time that his inheritance was grim, but at some point that starts to sound like an excuse for failure. If he is lucky, the Conservatives will help renew Labour’s licence to clear up a Tory mess by choosing an unrepentant leader who can’t offer a sincere account of why the party deserved to be defeated. Currently, all of the candidates fit that template. But the official opposition is not the prime minister’s main adversary. For now, he is racing the clock. He has promised tangible change to voters whose readiness to believe him will degrade while they experience life as more of the same. And there is no way of knowing how much time he has. There is no measuring patience. You only find out how much there was once it has gone. Rafael Behr is a Guardian columnist