Experts have warned that Britons should wear jumpers this Christmas and lower their heating to avoid the spiralling energy crisis.

Households need to stop being ‘t-shirt tweakers’ – those who wear thin tops with the heat blasting – and keep temperatures at no more than 21C indoors, they claimed.

The ‘Wear Warm’ campaign, backed by ex-footballer David James, fashion designer Wayne Hemmingway and Utilita Energy CEO Bill Bullen, also looks to tackle pollution.

It comes amid fears for the future of Britain’s seventh biggest energy firm Bulb – which specialises in supplying green power and heat.

The company, which has 1.7 million customers, is the latest victim to the soaring wholesale energy costs that have already forced the closures of 14 suppliers.

 The ‘Wear Warm’ campaign, backed by ex-footballer David James, fashion designer Wayne Hemmingway and Utilita Energy CEO Bill Bullen, also looks to tackle pollution

The ‘Wear warm’ campaign conducted research that found nearly half of British homes are heated to 24C, which is the same temperature as Barbados at this time of year.

It found that this was 3C higher than needed and added 13million tons of CO2 each year, the equivalent of seven millions cars.

The study suggested the overheating of homes was costing homeowners across the country £2.32billion a year extra – about £174 per house.

It was found that 51 percent of them were using additional heat sources such as a fan heater or oil-filled radiator, gas cooker, gas cooker, or electric blanket.

Bill Bullen, the founder and CEO at Utilita Energy said: “Energy bosses have been previously berated for daring suggest that consumers put on a jumper to stay warm, and on fuel poverty – this is not the right message.

“But there’s no excuse today’s government to ignore a simple don’t go over 21 degrees message’, just as we have.

“We are confident that our simple, effective message will have positive impact on the pockets and wallets of bill payers this Winter and will help Mother Earth – let’s make 2021 the last year we heat our homes to more than 21 degrees.”

He added on the Today programme: ‘We’re aiming this message at more affluent households.’

Founder and CEO of Utilita Energy Bill Bullen (pictured) said: 'Energy bosses and MPs have previously been berated for daring to suggest that consumers put a jumper on to stay warm, and on the subject of fuel poverty - it's not the right message'

Bill Bullen, the founder and CEO at Utilita Energy, said (pictured): “Energy bosses had previously been berated for daring say that consumers put a sweater on to stay warm. And on the subject fuel poverty – this is not the right message.

He said, “By wearing warmer clothes, we could actually make significant changes to climate change.”

“We need to be honest and pull out all of the stops to meet the targets we set. This small change could help the UK reach its net zero target two more years earlier.

When asked if it was more about saving money on energy companies, he replied: “Not at all, the UK have cut its energy consumption but we’re still going be dependent upon imported gas…

“So it’s about all customers understanding that everyone needs to do their part even if they can afford to heat their home a bit more, it’s not a good thing for energy prices or the environment.

Bullen stated that the firm will survive the winter, but that they had hedged their position many months ago before prices soared.

He said that gas prices had been falling since Russia announced last week that it was increasing European gas prices. However, they are historically high.

“We also took some other very sensible business actions a few months ago to ensure that if anything, we were slightly overhedged during this winter period. That so far has been working out for us.”

He stated that it was “almost certain” that there would be an additional significant increase to the price cap in April.

Research by the 'Wear Warm' campaign found nearly half - 48 per cent - of Britain's homes are heated to 24C seen in Barbados this time of year (file photo)

Research by the Wear Warm’ campaign revealed that nearly half of Britain’s homes are heated up to 24C, as seen in Barbados at this time of the year (file photo).

He added this could be about 12-13 per cent, which would mean about a 25 per cent rise over the two price rises, costing about £150 extra per household.

Archie Lasseter is a Utilita Energy global warming expert. If the UK turns down the heat, it will be able to reach its net zero obligation in two years.

He said: ‘If every household made a pledge to stay within 18-21 degrees, the UK would hit its net zero obligation almost two years ahead of its deadline.

Based on the fact that 48 per cent of UK homes are heated to 3 degrees above the recommended heat (18-21 degrees), we are generating an additional 13,000,000 tonnes of CO? Each year, we emit more CO.

He stated, “That’s about the same pollution as around seven million cars every year.”

Former footballer turned environmentalist Mr James said: ‘One of my personal bugbears is seeing people sitting at home in the winter, wearing a T-shirt, with the heating cranked up.

“There’s absolutely no logic in it, and now there’s evidence to prove the impact that such a behavior is having on the planet as well as the pockets.

“For example: To offset the pollution caused by overheated UK homes, we’d need 51 million trees per year – that’s enough for 392,000 football pitches.

Fashion designer Mr Hemingway said that it was obvious to add another layer. It makes sense for the environment, your health (cooler environments prevent the spread of many diseases), and your pocket. Why would you not? 

A third of households, 32 percent, who use an extra heat source, said they didn’t know if it was more expensive than using the central heating.

A third of respondents, 33 percent, said that they knew the heat source was more costly than central heating, but still use it.

It comes amid concerns for Britain’s seventh largest energy company Bulb, which specializes in supplying heat and green power.

The company, which has 1.7 million household customers, is the latest victim to the soaring wholesale energy costs that have already forced the closures of 14 suppliers.

Former footballer turned environmentalist Mr James (pictured) said: 'One of my personal bugbears is seeing people sitting at home in the winter, wearing a T-shirt, with the heating cranked up'

Mr James (pictured), a former footballer turned environmentalist, said: “One of my personal bugs is seeing people sitting home in the winter wearing a T shirt with the heating turned up.”

Firms complain that they are being squeezed by the official limit on energy prices. This prevents them from experiencing a sudden rise in prices.

COP26 is underway in the UK, where world leaders are gathering to promote green energy.

The Government supports price caps and insists they are vital consumer protection. Ofgem, an industry regulator, said Friday that it was open to reviewing how it works.

The current figure changes only twice a year, in April and October. However, this could be increased to every three to better reflect volatility in prices.

Bulb claims to be a green energy supplier but this does not make it immune from the price rise in fossil fuels.

All the electricity used by the company comes from renewable sources, such as windfarms. The firm also buys natural gases on the wholesale market.

It offsets the carbon emissions from this gas by supporting eco projects, such as planting trees.

Bulb disclosed on Friday that it was in talks for additional funding to secure its future.

If it fails, it will have to close and all its customers will be switched to a different supplier.

Bulb said that there has been some relief from the recent drop in wholesale prices.

However, the cost of gas on a day-ahead basis was 177p per therm on Friday morning, compared to 50p in April.

A spokesperson for the company stated: “Our discussions with multiple stakeholders continue to make good progress. We are encouraged by the fall in wholesale energy prices.

The current Ofgem cap means the typical household is be paying £1,277 per year. Without the cap, some analysts say households would be paying over £1,600 and potentially as much as £2,000.

The regulator emailed suppliers on Friday to say it was ready to examine how the cap works.

It stated: “The unprecedented rise of energy prices this year has changed our perception of risk in this market.

“In order for consumers to be protected, we must ensure the regulatory frameworks, which include the price cap, fully reflect all the risks and costs facing the supply companies that we regulate.