eir Starmer and Boris Johnson are such starkly different politicians that one thing they do have in common has gone almost unnoticed. The vision of Britain they’re offering, and how it might be achieved, can sound virtually identical. “We will build a Britain in which everyone has the opportunity to make the most of their talents,” said last year’s Tory manifesto. “I want … opportunities to be available to everyone,” said Starmer in his slick first party political broadcast last month. “Together, we can make [Britain] greater still,” promised the Tories. “Together, we can forge [a] better future,” promised Starmer. After a decade of acrimony, with the ideological gap between Labour and the Tories steadily widening until at the 2019 election it was possibly the biggest it has ever been, it’s a bit of a shock to find the two parties seemingly agreeing. Whereas under David Cameron, Theresa May and Jeremy Corbyn, the parties defined themselves against enemies (for Labour, “the privileged few”; for the Tories, “citizens of nowhere”, or people spending “a life on benefits”), now they’re trying to appeal to the entire electorate, and promising to satisfy every interest group. Both parties are selling national unity. Some of the reasons for this are straightforward. The pandemic has harmed the whole country. Labour, having lost the election, is trying to broaden its appeal, while the Tories are trying to hold together their winning coalition, with its many new working-class voters. But the sudden turn towards national unity also reveals more intriguing things about the state of the parties. Despite the Tory majority and Starmer’s promising poll ratings, both parties are anxious. Under new, inexperienced leaders, they face a fickle electorate. Over the four general elections since 2010, less than half of voters have stuck with the same party – the “highest levels of voter volatility in modern times”. The parties are also less sure than usual about what they believe in. Since 2010, Labour has switched from centrism to social democracy to socialism, and then to Starmer’s (so far) policy-free competence. Meanwhile, the Tories have swung between austerity and giveaway Covid spending, social liberalism and cultural conservatism, crony capitalism and “fuck business”. Despite all this frantic searching for the right formula, neither party can plausibly claim to represent the country. The Tories speak for most villages and towns, Labour for most cities. Neither speaks for Scotland. And Britain’s divisions go deeper than party politics, as the Brexit referendum exposed. Behind all the talk of healing these divides, two parties are casting their nets wide in the hope of scraping together enough votes. In an era of contempt for politicians and low election turnouts, the prospect of a genuinely unifying government feels remote. And that may not be a bad thing. In a country as unequal and full of competing interests, to claim we can create a better society simply by working “together”, as the Tories and Labour reverently put it, is unrealistic – even dishonest. If Starmer gets into power, he’ll discover that prime ministers have to pick sides. As the pragmatic centre-left French premier Pierre Mendès France once put it, “to govern is to choose”. And while Starmer is in opposition, he needs to appreciate that the preoccupation with national unity could become a trap for Labour. Every week at prime minister’s questions, Johnson urges him to support the government on coronavirus, hoping to make Labour complicit in its failures. Simultaneously, away from parliament, Johnson’s allies pursue a different, divisive strategy: the rightwing press constantly igniting culture wars, Dominic Cummings tirelessly concentrating power among a few favoured Conservatives and corporations. The art of politics is often to advance your side’s interests while appearing to care about everyone. The Tories can be good at this. Their promise to “level up” Britain is likely to direct resources towards new Tory voters in the north, away from Labour ones in London. Half-forgotten Labour schemers such as Harold Wilson and Herbert Morrison were good at this disguised tribal politics too. In Starmer’s TV broadcast there was a hint that he could become so as well. During his otherwise painstakingly even-handed, almost apolitical voiceover, he pointedly mentioned “the unfairness of our economy”. Some leftists hope this is code for an intent to follow ideas recently developed by John McDonnell and radical thinktanks: about how power could be taken from corporate executives and the City of London, usually aligned with the Tories, and given to the growing millions of precarious workers, who tend to vote Labour – or might be persuaded to. Offering to unite the country can make Labour leaders sound noble. But often only partisan Labour politics helps the poor pay their bills. Andy Beckett is a Guardian columnist