Latest figures show that during the week to October 16, 977,900 people were infected.
But the Scientific Advisory Group for Emergencies expects to see broader, flatter peaks in cases as the virus spreads, not one big spike.
However Sage said there were uncertainties around how people would behave and the impact of waning immunity.
Ministers have been told that acting early to tackle rising infections “would reduce the need for more stringent, disruptive, and longerlasting measures”.
Experts said the faster the epidemic grows, the harsher the restrictions must be to control it, according to minutes from a Sage meeting on October 14.
Sir Patrick Vallance, the chief scientific adviser, has said previously: “My mantra for a long time during this [pandemic] has been…you’ve got to go sooner than you want to in terms of taking interventions.
“You’ve got to go harder than you want to and go more geographically broad than you want to.”
Yet Health Minister Sajid Javid is resisting calls to implement the Government’s winter Plan B, which would see some curbs reintroduced. Sage told ministers to prepare to trigger the measures now, so they can be rapidly deployed if required. It said orders for people to work from home where possible are the most effective intervention.
Mandating face coverings in certain settings would help and requirements for vaccine certificates could encourage more people to get the jab. The Office for National Statistics estimated 977,900 people had the virus in the community last week – equivalent to one in 55, up from one in 60 the previous week.
There were 180 deaths within 28 days of a positive test reported yesterday, up from 115 the day before, while there were 8,238 patients on hospital wards – up from 6,366 – including 892 in intensive care.
Government scientists said the epidemic was growing by between one and three percent daily.
Meanwhile, officials are keeping a close eye on an off-shoot of the Delta variant becoming increasingly common in the UK.
The AY.4.2 lineage accounted for six percent of all Delta cases last week. The UK Health Security Agency said there was evidence it may have an increased growth rate compared to the original Delta variant. It does not appear to cause more severe symptoms or render any of the vaccines less effective.
Dr Jenny Harries, UKHSA chief executive, said: “Viruses mutate often and at random, and it is not unexpected that new variants will continue to arise, particularly while the case rate remains high.
“However, it should serve as objective evidence that this pandemic is not over.”
Meanwhile, almost nine in ten care homes have been visited or have appointments for booster shots, NHS England said yesterday.
Health Secretary Sajid Javid said: “I urge anyone eligible to book their booster vaccine.”