The UK should be braced for a coronavirus second wave as Covid cases spiked in the wake of relaxed lockdown restrictions, a World Health Organization expert has warned.
Dr David Nabarro, the WHO special envoy for the global Covid-19 response told Sky News the "the virus is going to come back" as "life gets going again".
Asked if a second wave was imminent, he replied: "It's coming.
"I don't like it calling it a second wave, I just say there are going to be more spikes and indeed some surges of cases because the virus hasn't changed.
"It's the same virus that came and caused so much trouble earlier this year.
"It's just been lurking, we've been very good at holding it back through restricting movement and lockdowns."
He continued: "Now as life gets going again, younger people are going to university, also there's some movement around with holidays and of course work - then I'm afraid it does mean the virus is going to come back."
Dr Nabarro's warning echos that of Professor John Edmunds - a member of the government's Scientific Advisory Group for Emergencies (SAGE) - who, in an interview with Robert Peston for ITV News, warned that coronavirus cases were "increasing exponentially".
Their warnings come after the number of cases in the UK reached 3,000 as of 9am on Monday, the largest rise since May.
Prof Edmunds, from the Faculty of Epidemiology and Population Health at the London School of Hygiene and Tropical Medicine, said that although we are all still socially distancing far more than we were before the virus arrived, we have not "hit the sweet spot" that allows more normal economic activity and simultaneous control of the spread of the virus.
He said that the autumn will be a challenge, because the rate of reproduction of the virus or R rate is above one - when schools and universities are re-opening. He raised the prospect not just of more local lockdowns but also of renewed national curbs on our freedoms - because opening schools and universities would have "an epidemiological effect" everywhere.
"I didn't want us to relax measures so much that we couldn't open the schools safely without it tipping the reproduction number significantly above 1. And we are already above 1 and we've opened schools. So this is a risky period".
He added: "The epidemic continues to increase and then we have Christmas. And that is very difficult. What is Christmas? Well it's meeting with your family very close. Restaurants and pubs and stuff like that. And it's all high risk. And it's all indoors. Indoors makes a difference."
He continued: "We've been lucky with the weather - and it's turned".
On Monday, the deputy chief medical officer of England Professor Johnathan Van-Tam warned that if the UK doesn't get its case numbers under control the country could have a "bumpy ride over the next few months".
Cabinet minister Robert Jenrick told ITV News that the growth in cases "reminds us all that we're still living with the virus."
He said: "We've all got to exercise good judgement, that means washing our hands, wearing a face mask, being socially distanced where we can.
"You can and should return to work, send your kids to school, use shops, cafes and restaurants and pubs, but make sure you follow the social distancing guidelines when you do."