Their warning comes after Prime Minister Boris Johnson announced a further easing of lockdown measures, with an end to the two-meter guidelines on social distancing.

In an open letter published by the British Medical Journal, supported by the presidents of the Royal Colleges of Physicians, Surgeons, GPs and Nursing, as well as the chairman of the British Medical Association, ministers are warned of a renewed outbreak over the winter.

The letter says: “Several countries are now experiencing COVID-19 flare-ups.

“While the future shape of the pandemic in the UK is hard to predict, the available evidence indicates that local flare-ups are increasingly likely and a second wave a real risk. Many elements of the infrastructure needed to contain the virus are beginning to be put in place, but substantial challenges remain.

“The job now is not only to deal urgently with the wide-ranging impacts of the first phase of the pandemic, but to ensure that the country is adequately prepared to contain a second phase.”

There is currently an increase in cases taking place in the U.S., with 27,465 new cases reported on Sunday, June 21, the second-highest Sunday on record.

The letter also calls for a “transparent rapid review” to establish “where we are and what needs to be done to prevent and prepare for a second wave” and for practical recommendations for action to be made.

It states: “The review should not be about looking back or attributing blame. Rather it should be a rapid and forward-looking assessment of national preparedness, based on an examination of the complex and interrelated policy areas listed below.

“These are too broad for anyone of the existing select committees. That is why a cross-party commission was suggested, establishing a constructive, non-partisan, four nations approach that could rapidly produce practical recommendations for action, based on what we have all learnt, and without itself becoming a distraction for those at the front line, or in government.”

It comes as Downing Street held its final daily briefing on COVID-19, in which the government’s Chief Scientific Adviser Sir Patrick Vallance and the Chief Medical Officer for England Professor Chris Whitty, stressed that the latest easing of lockdown measures, which allow pubs, restaurants, hair salons and many other businesses to reopen from July 4 in England, was not a “risk-free” move.

Whitty urged the public to remain cautious and said the country would have to “live with Covid-19 for the long haul until this time next year”.

He said: “I would be surprised and delighted if we weren’t in this current situation through the winter and into next spring.”

In the U.S., more than half of states have reported a rise in the number of COVID-19 cases, according to John Hopkins University, leading to fears over a second wave of infections and deaths.

In a rally in Tulsa on Saturday, President Trump said he had asked officials to limit testing, in order to reduce numbers of new cases.