A group of twelve residents have taken their plight to the Strasbourg court on behalf of the one million people who live and work around the volcano, which is close to Naples, the Italian news agency ANSA reported.

They say the evacuation plans are “inadequate” with many escape routes blocked by illegal building.

The move follows a warning by Japanese expert, Nakada Setsuya, who said “Vesuvius will erupt – that is certain, because it is an active volcano, even if we cannot predict when.” Setsuya was speaking during a volcano conference in Italy in September.

A report in National Geographic in August 2007 also said that current evacuation plans would not get people out in time if “the world’s most dangerous volcano”, which sits on a 154 square mile layer of magma, erupted like it did in 79 AD, burying the ancient Roman cities of Pompeii and Herculaneum and killing 20,000 people.

Vesuvius has erupted 30 times since then, most recently in 1944, when it killed 26 people. The most serious blast since Pompeii was in 1631, when it killed 4,000 people.

Naples officials have repeatedly played down reports that Vesuvius might be set to erupt, ANSA said.

Italy’s emergency procedure is based on four levels of alarm being given, with the evacuation of 550,000 people living in a 200 square kilometre “red zone” within 72 hours.

Once the volcano has erupted, residents living in the “yellow zone” will be evacuated if ash falls and gases released by the volcano pose a danger. However, the plan is reported to be based on one drawn up after the blast in 1631 and not the one which destroyed Pompeii.