Professor Carl Heneghan, director of Oxford University's Centre for Evidence-Based Medicine, believes the UK is moving towards the Swedish approach to dealing with COVID-19.
The PM blamed an uptick of cases on people breaking the existing guidelines, and warned that further breaches could mean a second national lockdown.
Watch: All you need to know about the new measures announced by the PM
The new measures include encouraging office staff to now work from home, pubs closing at 10pm and wedding attendance being cut from 30 to 15.
Heneghan said the measures, which have received overwhelming backing from 78% of people, according to a YouGov survey, reflected a “shift in policy” from trying to suppress coronavirus to trying control the spread of infection.
He told BBC Radio 4’s Today programme: “What you're starting to see is a move towards Sweden. For instance when you look at bars and restaurants – that's a policy there where they have table service.
An overwhelming 78% of Britons support the new lockdown measures announced today, including 44% who "strongly support" them.— YouGov (@YouGov) September 22, 2020
Just 17% of Britons are opposed...https://t.co/cwZ3vSKLpE pic.twitter.com/SUhCkAqC9e
“I'm hoping we now start to see a more coherent consistent policy, one that stays in place and that we don't keep seeing the changes we see almost daily that become utterly confusing to the public.”
He added: “We have two issues. One is the mantra of fear and we have enforcements and fines.
“Whereas back to the Swedish approach, they are much more supportive. For instance, if you test positive, you get two weeks’ full pay for staying at home.”
Watch: How to remove a face covering correctly
Heneghan said a lot of people “still don't understand what social distancing means”, which emphasised the need for a “clear message right through the winter”.
He said: “There will be an inevitable rise in cases as we go into winter. The key is not to panic now.
“You've got to let some of these measures work and they will take a few weeks to come through.
“If at every point there's an uptick in cases again and we panic with more measures, we'll talk ourselves into another lockdown – which is for the whole society hugely disruptive.”
Heneghan said he discussed the issues in a meeting with Johnson on Sunday night, adding: “It's about managing the policy throughout the winter.”
Restrictions in the country were voluntary, while authorities argued that the chances of finding a cue were slim and that allowing the population to develop herd immunity was a better strategy.
Restaurants and bars were not closed, while people were told to go to work when if they were able to.
Watch: What is ‘herd immunity’?
Schools for children under 16 remained open while gatherings of less than 50 people were permitted.
The wearing of face coverings has also so far not been recommended by the Swedish government.
Out of a population of over 10 million people, there have been 5,870 coronavirus deaths in Sweden, according to Johns Hopkins.
Daily new cases have remained stable, while data released this week showed Sweden has a fortnightly infection rate of 28 cases per 100,000 people – compared to 69 for the UK.