For the past month, the British people have been softened up like butter under a rolling pin for bad news about June 21.

Cautious Cabinet “doves” have been so successful that the only surprise Boris Johnson could spring next week would be to announce Covid curbs will be lifted after all.

As we now know, that is not going to happen, and the debate is already moving on to whether the delay will last for four weeks – taking us to July 19 – or even longer.

Doom-laden predictions of a catastrophic third wave following the reopening of schools in March and stage three of unlocking in May proved to be false, yet Boris Johnson has bowed to pressure this time from the very same voices who got it wrong before.

Government insiders say that while the latest figures on infections and the R-rate make for worrying reading, last-minute jitters from the Chancellor about lifting all restrictions have proved instrumental.

Until now, Rishi Sunak has been the cheerleader for unlocking, presenting the economic case for getting the country back to normal as quickly as possible. Among the “quad” of senior ministers making the key decisions, he was the hefty counterweight against risk-averse Matt Hancock and Michael Gove, with the Prime Minister completing the foursome.

But Mr Sunak believes the danger of lifting restrictions – only to have to reimpose them – would be far more damaging than a short delay.

The fact that he had already set aside money for a possible delay, by extending the furlough scheme to September, also means that in No 11 a short delay was already paid for.

“The Chancellor is quite relaxed about a short delay if that’s what’s necessary to win the race between the vaccines and the variants,” said one Whitehall source. “The reason he kept economic support in place until September was that he knew June 21 was the very earliest possible date for lifting remaining restrictions.

“For him the worst scenario would be to lift restrictions and then find a few weeks later we have to lock down again. That wouldn’t be good for health or for the economy.”

Many businesses might disagree, including those that have taken out loans predicated on business returning to normal on June 21. Retail, leisure and hospitality businesses will also have to start paying one third of their normal business rates from July 1, after the 100 per cent exemption expires.

For pubs, restaurants, airlines, wedding venues and a welter of other businesses, June and July are not just any old months, they are peak profit season, and if they miss out on the bounty of a sun-kissed summer they might collapse under the weight of their own debts.

Boris Johnson’s insistence that he could see “nothing in the data” to merit a delay now seems like the distant past, even though Downing St repeated the mantra as recently as last Monday.

The data has undoubtedly changed: although fully-vaccinated people account for just 5 per cent of infections of the Indian – or delta – variant, cases have jumped from 9,426 to 33,206 in the space of a week (below). Friday’s total of 8,125 was the highest for four months.

Just five per cent of Delta variant infections are in people who have been fully vaccinated

There are fears among ministers that they would have to shoulder the blame for any increase in deaths – and so-called long Covid cases – if they chose to ignore the rise in infections, and data on transmissibility of the Indian variant, which Whitehall sources say could be more than 60 per cent more infectious than previous strains, will not be ready before Monday’s announcement of a decision on June 21.

There are those who have been fighting their own battle to extend restrictions for weeks.

Prof Ravi Gupta, a member of the New and Emerging Respiratory Virus Threats Advisory Group (Nervtag) was lobbying last month for ministers to push back reopening by “a few weeks”, while Chris Hopson, of NHS providers, and Prof Neil Ferguson, of modelling committee SPI-M, have repeatedly warned of a risky third wave if June 21 goes ahead, and a grim-faced Mr Hancock has spent the past month saying the Government “will not hesitate” to take further action to curb the Indian variant.

Covid cases projection – June 21

Theresa May, the former prime minister, is among those who have warned that if the Government curbs freedoms every time a new variant emerges, life will never get back to normal.

But one of the biggest stumbling blocks is research showing that both the AstraZeneca and Pfizer vaccines are only 33 per cent effective against the Indian strain after a single dose, forcing a recalibration of timings, which had previously been based on the idea that a single dose was 65 to 80 per cent effective.

The impact of the blood clot scare on the vaccination programme also continues to be felt. Because Pfizer or Moderna jabs must now be offered to under-40s instead of the AstraZeneca vaccine, which has been linked to rare cases of blood clots, it has been impossible for the Government to speed up delivery of the vaccines, which had been weighted towards the use of the British-made jabs.

Few in Government are now talking of anything other than a four-week delay.