A return to life as normal could fuel an autumn wave of coronavirus cases but further lockdowns may not be required, a Government scientific adviser has said.

Professor John Edmunds, a member of the Scientific Advisory Group for Emergencies (Sage), said he was “cautiously optimistic” that another lockdown would not be needed to bring cases under control again.

Prof Edmunds said there was a need to be “very cautious” about the situation at the moment because previous peaks had been countered by locking down.

If we go back completely to normal that will certainly fuel an autumn wave

“We’re not doing that this time,” he told Times Radio. “But I don’t think we will need to go into a lockdown. I hope not anyway. I very much hope not.

“I’m cautiously optimistic about that.”

Infections are expected to rise again in September, when school and university terms begin and more workers are expected to return to the office.

Prof Edmunds said: “Will we ever return to completely normal behaviour? I don’t know.

“But there’s a long way to go between the sorts of behaviours that we’re collectively making now and the average behaviour that we were making before the pandemic. There is a big difference.

“If we go back completely to normal, that will certainly fuel an autumn wave.”

Fellow Sage member Professor Neil Ferguson, among the Government’s most prominent scientific advisers on Covid, also predicted it is unlikely a lockdown will be needed again to control the virus.

In an interview with the Times, he said: “I think it is unlikely we will need a new lockdown or even social distancing measures of the type we’ve had so far.”

The Imperial College professor also told the newspaper that lockdowns could not be ruled out as they may still be needed if the “virus changes substantially”.

However, Prof Ferguson added that Covid was “going to transition quite quickly in a few months to be more something we live with and manage through vaccination rather than crisis measures”.

He said the vaccine had “dramatically changed the relationship between cases and hospitalisation”.

Prof Ferguson also said the Euro 2020 football championship had created an “artificially inflated level of contact”, leading to his predictions in July that the UK would hit 100,000 Covid cases a day following phase four of unlocking.

After the tournament ended cases decreased and Prof Ferguson said the pingdemic also had a “reasonable effect” on making it harder for the virus to spread.

The optimistic assessment from the leading scientists came as people in Wales enjoyed new freedoms as lockdown eased there.

From 6am, all restrictions on meeting others were removed and all businesses, including nightclubs, reopened.

Face masks will continue to be required on public transport, in health and social care settings, and in shops.

Venues will be required by law to undertake coronavirus risk assessments, intended to encourage businesses to keep in place measures such as ventilation or social distancing where necessary to keep staff and customers safe.

Adults who are fully vaccinated and young people under the age of 18 will no longer need to isolate if they are a close contact of someone who has coronavirus.

But people must continue to isolate for 10 days if they have symptoms of Covid-19 or if they have a positive test result.

Meanwhile, Downing Street was forced to deny reports that Boris Johnson had come into contact with an aide who tested positive for Covid during a two-day tour of Scotland.

The Guardian had reported that a Number 10 official taking part in Mr Johnson’s visit to Scotland had to isolate after testing positive.

The newspaper said the two had been seen “side-by-side” on several occasions, yet Mr Johnson is not isolating.

A Number 10 spokesperson said: “The Prime Minister regularly visits communities across the UK and all aspects of visits are carried out in line with Covid guidance.

“The Prime Minister has not come into close contact with anyone who has tested positive.”

Labour’s Anneliese Dodds criticised the Prime Minister, describing the decision as “another example of one rule for them and another for everyone else”.

The coronavirus reproduction number, or R value, in England has fallen and is between 0.8 and 1.1, according to the latest Government figures.

Last week, it was between 1.1 and 1.4. R represents the average number of people each Covid-19 positive person goes on to infect.

The latest Government figures showed:

– Up to August 6, some 46,997,495 people have received a first dose of vaccine, a rise of 35,665 on the previous day, while 39,210,356 have now had two doses, an increase of 162,827.

– A further 103 people had died within 28 days of testing positive for Covid-19 as of Saturday, bringing the UK total by that measure to 130,281.

– As of 9am on Saturday, there had been a further 28,612 lab-confirmed Covid-19 cases in the UK.