British Energy said that it would be forced to buy electricity on the wholesale market to meet its supply contracts after discovering cracks in boilers at Hinkley Point power station.

Although the company maintained that there was no radiation safety risk its shares plunged on the stock market. British Energy supplies a fifth of the country’s power from its fleet of ageing nuclear reactors.

The spot price of gas fell on the market as the Prime Minister launched Langeled, the world’s longest subsea pipe, a vital piece of infrastructure that will bring fuel from Norway, helping to fill a supply gap caused by the dwindling output of Britain’s North Sea fields.

The emerging shortage caused extraordinary surges in the gas price last winter, forcing businesses to close and prompting National Grid, on March 13, to make its first Gas Balancing Alert, a warning that the network was dangerously short of gas.

Mr Blair made his call for action on energy as he celebrated in London with Jens Stoltenberg, the Norwegian premier, the opening of the Langeled terminal at Easington in Yorkshire.

He said: “Where we replace our energy from is going to be a huge thing . . . if we don’t get the question of energy security right now, in this period of time, we will pay a heavy price in the future for our economy and for our consumers.”

The opening of the 875-mile Langeled pipe coincided with a government consultation on gas security.

Malcolm Wicks, the Energy Minister, said that by 2020 more than 80 per cent of Britain’s gas could be imported. Mr Wicks said that it was the energy industry’s job to deliver security of supply, but the Government needed to make sure that Britain had the right regulatory framework.

Norsk Hydro, the lead company in the Langeled project, will be piping gas from Ormen Lange at full capacity within a year. Pumped at a rate of 70 million cubic metres per day, it will carry enough fuel to supply a fifth of Britain’s daily need.

The project, which cost more than £5 billion, involved major feats of engineering and required the capacity of three steel mills to produce a million tonnes of pipe. The gasfield has no surface platform but uses new technology to control the wells from a manifold on the seabed at depths of more than 1,000 metres.

A leading energy consultant claims that inaction by the British Government caused delays in bringing Ormen Lange gas to Britain.

According to Simon Blakey, a senior director of CERA, the energy consultancy, Langeled would have been completed a year ago and contributed to lower British gas prices but for delays from Whitehall.

“The clearest example of this was the process by which the British Government, from 2001 to 2003, dragged out discussions with its Norwegian counterparts on tax and other issues,” he said.

Since the summer, wholesale gas prices have fallen due to warm weather and anticipation by gas traders of the completion in October of the southern section of the Langeled, which joins Sleipner, a gas production platform and pipeline hub in the North Sea. The full benefit of the new import capacity won’t be felt until completion of the northern section, expected in October next year, when Langeled will tie Ormen Lange, a giant gasfield 87 miles off the west coast of Norway, directly into the British gas grid.

Pressure tests of Langeled in September caused the spot gas price to collapse as engineers pumped huge volumes through the pipe to check for leaks. So much gas was injected into the network that National Grid was forced to pay companies to remove gas from the grid, causing the spot price to fall briefly to minus 5p per therm.

Consumer groups have called for action by retailers to pass on the benefit of falling wholesale prices. Karen Darby, chief executive of SimplySwitch said: “Domestic gas users have seen their bills go up by an average of 80 per cent for gas and 53 per cent for electricity since the start of 2004.”

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