Total, one of the world’s largest oil companies, has been accused of hiding behind a “completely ludicrous” legal argument to avoid responsibility for Britain’s biggest peacetime explosion.

The accusation was made yesterday at the High Court where the company is facing up to £700 million in claims arising from the blast at the Buncefield fuel storage depot in Hertfordshire in December 2005.

Total and Hertfordshire Oil Storage Limited (HOSL), which operates the Buncefield plant, have been sued by a host of insurance companies, businesses and around 270 residents of Hemel Hempstead. BP and Shell, which also had operations at the plant, are also claiming substantial damages.

Opening the case on behalf of the claimants, Jonathan Gaisman, QC, accused Total of using legal manoeuvres “bereft of merit” in an effort to avoid culpability.

Earlier this year, Total admitted in preliminary hearings that the blast was the result of negligence by the supervisor on duty at the time. However, it has only accepted liability for properties within 451 metres of the blast on the grounds that damage to property beyond that could not have been predicted.

Claimants whose properties lay further than 451 metres from the site of the explosion will have to prove that damage to their properties was foreseeable. That includes more than 170 local residents and small businesses.

Mr Gaisman said that Total's argument was legally unprecedented and based on flawed calculations. “Even a child” could have guessed that an explosion of such magnitude would cause damage to properties within several kilometres of the plant, he said.

Local residents crowded into the courtroom alongside dozens of lawyers and watched as chilling closed-circuit television footage showed the air around the plant filling with petrol vapour in the moments before the blast.

Forty-three people were injured in the explosion, which occurred after a petrol tank overflowed. It registered 2.4 on the richter scale and caused "widespread and catastrophic damage", the court heard.

Lawyers said that the case, which has already cost more than £60 million according to one estimate, could be overshadowed by a “private spat” between Total and Chevron, its joint venture partner in HOSL.

Total claims that Chevron, which owns 40 per cent of HOSL, should share liability for the supervisor’s negligence.

However, Chevron is expected to argue that it was merely a silent partner in the venture and had no responsibility for its day-to-day management.

The court heard that residents of Hemel Hempstead had endured a “terrifying experience” and were still suffering mental and physical distress. One family was forced to move into a hotel on four separate occasions while their home was rebuilt.

Ninety-five per cent of personal injury claims had yet to be settled, the court heard.

The trial is scheduled to last 13 weeks.

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