BORIS Johnson has been branded “missing in action” after reports that he will skip emergency Cobra meetings as the UK braces for an unprecedented heatwave.

Ministers will hold a second emergency meeting on Saturday after meteorologists warned of record high temperatures that could put lives at risk.

Cabinet Office minister Kit Malthouse is to chair a meeting of the Government’s Cobra civil contingencies committee to discuss the escalating heatwave, a Government spokesperson said.

It will be the second Cobra meeting Malthouse has led on the issue.

READ MORE: Scotland issued amber extreme heat warning by Met Office for Monday and Tuesday

Meteorologists have given an 80% chance of the mercury topping the UK’s record temperature of 38.7C set in Cambridge in 2019, with the current heatwave set to peak on Tuesday.

Temperatures will climb over the weekend, and the Met Office has issued an amber warning for heat covering Scotland, England and Wales.

A red warning of extreme heat was also issued for the first time ever, covering many of England’s largest cities.

As people prepare for the heat, Labour criticised Johnson after reports said he had failed to attend Cobra meetings.

Angela Rayner, Labour’s deputy leader, said: “Boris Johnson has gone missing in action again. He’s back to his old tricks of skipping important Cobra meetings.

“Where’s the plan for the delivery of essential services and how people will be kept safe at work, on transport, in schools, hospitals and care homes?

“The public will have no confidence in this zombie Conservative government responding swiftly and decisively to this national emergency as this disgraced Prime Minister prepares to party while Britain boils.

“If he still can’t take the responsibility of the job, he should leave right now.”

Speaking on Friday, Johnson's official spokesperson refused to confirm the interim prime minister would attend Cobra meetings, saying only that he "is kept up to date with all the latest information".

The outgoing prime minister faced criticism after reports that he had skipped five Cobra meetings at the start of the Covid pandemic.

READ MORE: UK temperatures 'could break 40C for first time ever' as heatwave hits

Daytime temperatures on Saturday are predicted to be around 27C in London, 26C in Cardiff, 23C in Belfast and 21C in Edinburgh.

On Sunday, it could reach 30C in the capital, 27C in Cardiff, 24C in Belfast and 23C in Edinburgh.

Temperatures are forecast to increase by several more degrees on Tuesday – up to the mid-30s for much of England and Wales.

There is a 50% chance of temperatures reaching 40C somewhere in the UK, likely along the A1 corridor which runs from London to Scotland through counties including Lincolnshire, Nottinghamshire, Yorkshire and the North East, with the Met Office issuing its first ever red warning for extreme heat.

The UK Health Security Agency has increased its heat health warning from level three to level four – a “national emergency”.

Level four is reached “when a heatwave is so severe and/or prolonged that its effects extend outside the health and social care system… At this level, illness and death may occur among the fit and healthy, and not just in high-risk groups,” it said.

A Met Office red warning, for Monday and Tuesday, covers an area from London up to Manchester, and up to the Vale of York.

Met Office spokesman Grahame Madge said: “If people have vulnerable relatives or neighbours, now is the time to make sure they’re putting suitable measures in place to be able to cope with the heat because if the forecast is as we think it will be in the red warning area, then people’s lives are at risk.

“This is a very serious situation.”

Britons have meanwhile been scrambling to buy fans and looser clothing to help them keep cool during the heatwave.

Retailer Toolstation said sales of fans have risen by 641% over the last week compared with the week before as tradespeople struggle to stay cool.

The company also said sales of builders’ shorts have increased by 50% and t-shirts by 35%.