In the starkest warning yet England's chief medical officer has said the nation faces a "very challenging winter" as coronavirus cases are set to reach 50,000 a day by the middle of next month.

His announcement this morning precedes an expected tightening of restrictions as fears of a second lockdown grow.

He told the public Britain stands at a “critical point”, with the current trend heading in “the wrong direction”. On Sunday 3,899 new cases were recorded but in Kent figures fell by a third.

There is believed to be 70,000 active cases in the UK, with 6,000 new infections a day, according to the Office for National Statistics.

Boris Johnson spent the weekend with senior ministers and advisers discussing what action to take as the rise in the number of new cases showed no sign of slowing.

It is thought the Prime Minister could announce new measures in a press conference as early as tomorrow.

Prof Whitty, who appeared alongside the government’s chief scientific adviser Sir Patrick Vallance, explained how the virus is spreading in the UK and the potential scenarios that could unfold as winter approaches.

They drew on data from other countries such as Spain and France, which are experiencing a second surge, to underline how their experience could be replicated in the UK.

Prof Whitty said: “The trend in the UK is heading in the wrong direction and we are at a critical point in the pandemic.

“We are looking at the data to see how to manage the spread of the virus ahead of a very challenging winter period.”

Sir Patrick said ONS data shows cases are doubling "roughly" every week.

At this rate the virus "could" infect 50,000 a day by the middle of October and kill more than 200 a day by November, he warned.

"The seasons are against us," said Prof Whitty, adding: "This is a six-month problem and eventually science will ride to our rescue. We collectively need to take this very seriously. There is no evidence the virus is more mild than it was in April."

Addressing concerns people are becoming complacent due to them being low risk, he said: "You cannot in an epidemic just take your own risk.

"We need to reduce our individual risk, washing hands and wearing masks in places that are contained and maintaining space between people especially when in doors.

"If people have symptoms they must self-isolate, this means they are taking a big step forward on behalf of society in the fight against the virus.

"We need to reduce unnecessary contacts between households. If we don't do enough the virus will continue on the trajectory it is on."

Ministers were reported to be split on how far any new restrictions should go, with Chancellor Rishi Sunak said to be resisting controls which could further damage the economy.

During a series of broadcast interviews over the weekend, however, Health Secretary Matt Hancock refused to rule out a second national lockdown in England, if people fail to follow the social distancing rules.

He said he feared cases could go “shooting through the roof” with more hospitalisations and more deaths.

Meanwhile London mayor Sadiq Khan is to meet council leaders in the city today to discuss possible new restrictions in the capital, which they would then put to ministers.

“The situation is clearly worsening,” a spokesman for the mayor said.

“The mayor wants fast action as we cannot risk a delay, as happened in March. It is better for both health and business to move too early than too late.”

Another 3,899 lab-confirmed cases of coronavirus in the UK were announced on Sunday, while a further 18 people died within 28 days of testing positive, bringing the UK total to 41,777.

The latest figures came after the Government announced anyone in England refusing to obey an order to self-isolate could face a fine of up to £10,000 and just days after the “rule of six” – banning social gathering of more than six people – came into force.

Mr Johnson has been desperate to avoid another nationwide lockdown amid concerns about the economic damage it will inflict just as activity was beginning to pick up again.

However, as of Tuesday, about 13.5 million people across the UK will be facing some form of local restrictions, including 10pm curfews for pubs and restaurants, as the authorities grapple with the disease.

Among the measures being considered by ministers is a temporary two-week “circuit break”, with tighter restrictions across England in an attempt to break the chain of transmission.

The Government is facing resistance from some senior Conservative MPs concerned that ministers are taking increasingly stringent powers with little or no parliamentary scrutiny.

Sir Graham Brady, chairman of the powerful Tory backbench 1922 Committee, said he will table an amendment which would require the Government to put any new measures to a vote of MPs.

Sir Keir Starmer said Labour would support any new measures but warned that a second national lockdown was becoming more likely because the Test and Trace programme was in a state of “near collapse”.

Mr Hancock said with hospital admissions for the disease doubling “every eight days or so”, further action was needed to prevent more deaths.

“This country faces a tipping point,” he told BBC One’s The Andrew Marr Show.

“If everybody follows the rules – and we will be increasingly stringent on the people who are not following the rules – then we can avoid further national lockdowns.

“But we of course have to be prepared to take action if that’s what’s necessary.”

Under the latest rules, from September 28 people in England will have a duty to self isolate for 14 days if they test positive for coronavirus, or they are instructed to do by NHS Test and Trace because they have been in contact with someone with the disease.

Fines for non-compliance will start at £1,000, rising to £10,000 for repeat offenders in the most “egregious” cases.

People on benefits will be eligible for a one-off support payment of £500 if they face a loss of earnings as a result of being required to quarantine.

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