The fiscal constraints under which a new Labour government would operate in the next parliament mean that, before too long, Keir Starmer and Rachel Reeves will be compelled to raise taxes. The alternative is a return to austerity, which would be unconscionable for the Labour leadership and punish those whom the party aspires to represent above all others: Britain’s fabled “working people”.

But the charade goes on. The front bench repeats with iron discipline its mantra that Labour will not raise income tax, VAT or National Insurance if it wins on 4 July, as it will resoundingly. On this Reeves means what she says. But when it comes to, say, raising capital gains tax, or re-evaluating council tax charges, or even introducing wealth taxes, she and her colleagues are equivocal. This, then, is what economists are calling Labour’s “conspiracy of silence” over tax and the state of public finances.

One understands the reason for Labour’s lack of candour. Why would Starmer and his team wish to disturb their own serene glide towards power? Labour strategists cannot believe their luck at how dismal the campaign has been for the Conservatives. Rishi Sunak, less than three weeks out from the final vote, and usually so stridently self-confident, has the demoralised look of a man already mourning his own defeat. For the Prime Minister, most certainly since the D-Day commemorations debacle, this has become a protracted campaign of masochism: he goes on because he has no alternative but to go on. Until the electorate ends his misery.

Labour knows it will win but remains excessively cautious, in part because it has been traumatised by repeated election defeats as well as the civil war that consumed the party during the Corbyn years. Starmer may have served under Corbyn until the final, abject defeat but this, he shiftily told Beth Rigby during the Sky leaders’ debate on Tuesday evening, was only because he knew the veteran agitator would lose. Does anyone believe him?

Starmer had other reasons for staying on. First, he understood that as an anti-Corbyn dissenter he could never win the leadership of a party that had been captured by the radical left. Second, back then, he was a committed Remainer. He sensed an opportunity to reverse the vote for Brexit and persuaded John McDonnell, Corbyn’s shadow chancellor and the de facto leader of the left in parliament, to support a second referendum. But now Starmer seldom mentions the European Union other than to reiterate that Brexit is a settled matter.

Labour’s problem then is not so much a conspiracy of silence as a crisis of trust. Who or which institutions do the public believe will change their lives for the better? Labour says it will not raise taxes, but we know it will. Sunak says he will reduce immigration, but we know he cannot, just as David Cameron could not before him, despite pledging to reduce net migration to below 100,000 a year.

Trust, and its absence, was the fork on which Beth Rigby expertly skewered Starmer and Rishi Sunak in her interviews with both men. She wanted them to concede that they said one thing and did another; that promises and pledges existed only to be broken in politics. Why pretend otherwise?

There is a restive mood in the country as there is elsewhere in Europe as the hard right advances in Germany, France and Italy in particular. Labour should be very careful. The party’s support is broad but shallow: turn-out may be low on 4 July and it may even win fewer votes in aggregate than Corbyn’s Labour did at the 2017 election. One of the failings of the first-past-the-post system is that it exaggerates the margin of victory: the winner really does take it all.

But there is a deeper political tide turning beneath this approaching result. Trust and confidence in British politics and our elected politicians is at an all-time low, according to a National Centre for Social Research report published this week. “The public is as doubtful as it has ever been about the trustworthiness and efficacy of the country’s system of government and the people who comprise it,” said John Curtice, the polling expert and author of the report.

Nigel Farage has always had a feeling for the social atmosphere of the country. He is determined to exploit an anti-Tory mood of mass disaffection, especially among leave voters. “I’ve been thinking that Brexit might not be the last [political] earthquake,” he told me in 2017. “There might just be another one. There may be something seismic still to come. And it could be the Conservative Party that’s the most vulnerable to it.” This election shows he was right about that. Now he says: “Something remarkable may happen on election day. We are on the verge of shifting the tectonic plates of politics.”

Labour will benefit from the Conservative collapse in Farage’s metaphorical earthquake. But Starmer’s government will immediately face multiple crises: weakened state capacity and a fragile civil service, real-terms public spending cuts that will come into effect from 2025, a hard right insurgency in Europe, geopolitical disorder from the Red Sea to the Taiwan Strait. This is emphatically not the dawn of a new progressive liberal world order that was celebrated by Tony Blair in 1997.

What Jonathan Powell, chief of staff in the Blair government, called the “post-euphoria, pre-delivery phase” of government is vanishingly brief. Keir Starmer’s Labour will be revealed soon enough by the choices it makes in power.

The hard lesson of these recent years of post-Brexit upheaval is that it’s not enough to say what your intentions are – that’s the easy part of campaigning. Many politicians have good intentions. Some even mean what they say. But what matters in leadership is not what you say – or pledge and promise as Rishi Sunak has brutally discovered - but what you do and how competent you are. “People need to trust a leader’s competence,” writes the economist Paul Collier in his new book, Left Behind. That word again: “trust”. But trust in politics and politicians has never been lower. Labour have had fair warning.