People should “prioritise what matters to them” when considering attending parties and other events during the Christmas period, Professor Chris Whitty has said.

Boris Johnson said he agreed with England’s chief medical officer about people being cautious and told the public to “think carefully before you go” to celebrations, as the Omicron variant surged.

Their warnings at a Downing Street press conference were quickly met with calls for greater support for the hospitality industry, as people weigh up whether to risk nights out or cancel and spend Christmas with their families.

The UK recorded the highest daily total of lab-confirmed coronavirus cases since the pandemic began when 78,610 new cases were announced on Wednesday.

Prof Whitty told people “don’t mix with people you don’t have to” at events that are not among the most important to them.

“I really think people should be prioritising those things – and only those things – that really matter to them,” he said.

“Because otherwise the risk of someone getting infected at something that doesn’t really matter to them and then not being able to do the things that matter to them obviously goes up.

“I don’t think you need to be a doctor to think that, I think that’s what most people are very sensibly calculating and that seems to me a sensible approach.”

The Prime Minister declined to go as far as Scotland’s First Minister Nicola Sturgeon who has given specific guidance to urge people to limit their socialising to three households before and after Christmas.

But he said: “I agree totally with Chris about the response we’re already seeing from everybody, our general instinct to be more cautious.

“I said many times that I thought this Christmas will be considerably better than last Christmas and I stick to that. We’re not cancelling events, we’re not closing hospitality, we’re not cancelling people’s parties or their ability to mix.

“What we are saying is think carefully before you go. What kind of event is it? Are you likely to meet people who are vulnerable, are you going to meet loads of people you haven’t met before? And get a test.”

Almost immediately, British Chambers of Commerce president Baroness Ruby McGregor-Smith warned of the potentially devastating impacts the remarks may have on the hospitality sector.

“The need for the chief medical officer to advise the public to ‘de-prioritise social contacts’ at tonight’s press conference will almost certainly have an enormous impact for businesses, particularly in the hospitality sector,” she said.

“Despite this still we heard no news of any new financial support measures coming from Government to help those businesses, and others badly affected by the current restrictions.

“Until now the Treasury has stepped up at every stage of this crisis to help offset restrictions that limited business’ ability to trade fully, which is what makes its complete absence at this crucial moment all the more baffling.”

Tory MP Anne Marie Morris added: “If we’re effectively telling people not to visit hospitality venues this Christmas, then this needs to be accompanied by immediate sector specific financial support from the Treasury.”

Professor Stephen Reicher, who advises the Government as part of the Scientific Pandemic Insights Group on Behaviours (Spi-B), said Mr Johnson declining to be as explicit as Prof Whitty was an instance of mixed messaging.

“It’s deeply problematic that the Prime Minister is in the position where he can’t say to people – as the chief medical officer did – look, just don’t go out socialise if you don’t want to,” he told Channel 4 News.

“He couldn’t say don’t go to nightclubs if you want to meet your loved ones at Christmas, and I think that leads to mixed messaging which is really problematic because the clear message that needs to go out to everybody is yes get your booster, that will work in a few weeks’ time, but now to stop the new variant taking over be cautious, be careful, don’t socialise unless you have to.”