The National Grid was forced to enact emergency measures to stave off the threat of shortages and politicians and consumer groups have called for major investment in infrastructure to secure the country’s future.

Households could face crippling energy bills, localised blackouts and widespread disruption unless action is taken, consumer groups warned.

The Arctic weather gripping the UK has caused a 30% rise in demand for gas over and above normal winter levels, putting extra strain on the grid and necessitating emergency imports from Norway and Belgium.

The National Grid issued a Gas Balancing Alert (GBA) on Monday – only the second time it has ever had to do so – and it said that although the situation has now stabilised it will continue to monitor supplies.

The GBA is a way of telling larger customers to limit their consumption while also encouraging greater input from suppliers, but because of limitations in the gas storage capacity the UK is left more exposed to shortages than many experts would like.

The Conservative Party claimed that Britain had only eight days’ gas supply left and Shadow Energy and Climate Change Secretary Greg Clark criticised the Government for having had “its head in the sand on this issue for 12 years”.

“I have repeatedly warned that Britain lacks the essential back-up plans needed for situations like this one,” he said, adding: “When will the Government understand we need more storage capacity and the ability to get gas to consumers so nobody has to face the possibility of going without gas during cold snaps like this one?”

The Government, however, accused the Opposition of scaremongering. A spokesman said: “There is no risk of consumers being cut off. The system has in fact been responding well. Britain has a vast amount of storage – it’s called the North Sea.”

But Jeremy Nicholson, director of the Energy Intensive Users’ Group – an umbrella body representing some of the heaviest industrial users of energy – said companies and, ultimately, consumers, were already paying the price for shortcomings in the power industry.

He said: “We got away with it this winter because, internationally, supplies of gas are plentiful – largely because of the recession. If this cold snap had occurred at a time when energy was at near full production, we could have been in trouble.”

While energy producers have been able to fall back on burning coal in place of gas, this will not be an option in future, he added, as the UK’s energy mix changes. A broad base of renewables will be needed to meet demands but some groups believe that nuclear plants will also be necessary.

Though Mr Nicholson said it was important not to be “alarmist”, he added: “When we’re 24 hours away from rationing gas, it’s not a trivial thing. The important thing is that we learn the lessons from this.”

Concerns were also raised by John Holmes, of consumer group Which?, who accused authorities of taking “a haphazard approach that risks leaving consumers with an excessive bill”.

He called on the Government to introduce a “clear strategy” to tackle the problem and warned that the credit crunch had left consumers unwilling to trust essential services solely to the whims of the market. “We can’t afford to take a chance on securing our energy supplies,” he said. “It’s hardly a situation you want to be in in a modern economy, where you risk blackouts.”

Gas and electricity watchdog Ofgem has already launched an in-depth review of national energy supplies and said in October that it could require a £200 billion investment to meet all national objectives. A spokesman said the report, which will not be completed until later this year, will focus specifically on energy security in the medium to long term.

The National Grid yesterday insisted that the alert issued on Monday had been a success, but their spokesman acknowledged that storage capacity was limited and would be costly to increase.