How many pupils return to school in September will provide a poll on the public’s trust in Boris Johnson

This week the government will launch a new national advertising campaign. Not for a new product, not to urge businesses to prepare for Brexit, but to encourage parents to send their children back to school.

Boris Johnson has staked an enormous amount of political capital on his pledge to get every pupil in the classroom in September.

The prime minister has declared it a moral duty to get children back behind their desks.

Last week he went even further, suggesting the move was crucial to kick-starting the British economy.

With so much riding on the reopening of schools, therefore, government insiders will have been dismayed at a recent poll suggesting trepidation among the nation’s parents.

Should it come as a surprise?

Ministers were, after all, shocked at how quickly and staunchly the public took to lockdown.

Estimates of how many employees would continue to go to work had to be swiftly junked after only a fraction of the workforce turned up.

Schools that had expected to be packed with the children of key workers saw very few of them arrive.

Even in March it was clear the public was more frightened of Covid-19 than government experts had predicted.

At that stage, however, polls also suggested there was a high level of trust in the government and its actions against the global pandemic.

Exhorted to stay home and protect the NHS, the British public did just that.

But by the start of this month, when they were urged to go back out to work by the same prime minister, the public did not listen.

Polls now suggest that trust in ministers’ decisions was dented by one dramatic incident, the decision of Dominic Cummings, the prime minister’s chief adviser, to apparently break lockdown rules with a trip to Durham.

In the run-up to the lockdown declaration, government experts warned ministers they had to be incredibly careful about the timing, because public trust would be one of the UK’s strongest weapons in the battle against coronavirus.

This autumn, as the government pledges to both “build back better” and prepares to fight a potential second wave of the disease, England’s classrooms might just be a test of how much parents currently trust politicians.