Prof Neil Ferguson said it was “almost inevitable” that Monday’s final phase of unlocking would bring on 100,000 daily cases, with about 1,000 hospitalisations – despite roughly half the UK being fully vaccinated. He added that he could foresee a situation in which the case rate expands to twice the size.

“The real question is do we get to double that – or even higher,” he told BBC One’s Andrew Marr Show on Sunday,. “And that’s where the crystal ball starts to fail. I mean, we could get to 2,000 hospitalisations a day, 200,000 cases a day – but it’s much less certain.”

Daily hospitalisations surpassing 2,000 a day is equivalent to the level in the week leading up to Christmas. Although people currently being hospitalised do not fall as severely ill, and are much less likely to die, Ferguson said that “if you have enough cases, you can still have quite significant burden on the healthcare system … major disruption of services and cancellation of elective surgery and the backlog in the NHS getting longer and longer.”