Charles and Camilla launch electricity superhighway

The Prince of Wales was left with tunnel vision during a trip underground to see a billion-pound project that has future-proofed London's electricity supply for decades.

Charles descended 16 flights of stairs to marvel at a network of tunnels carrying huge cables under the capital's streets, while Camilla stayed on the surface to learn about the National Grid's electricity superhighway scheme.

Wearing a hard hat, high visibility jacket and heavy duty gloves the heir to the throne walked along a small section of the 20 miles of concrete-lined passages, bored out during the seven-year project.

When Charles was asked to pose for a picture he looked back at the cables disappearing into the distance and quipped "tunnel vision".

John Pettigrew, National Grid's chief executive, gave the prince a brief guided tour of some of the tunnels 105ft (32 metres) below the surface.

In a speech at the launch event, held at Highbury sub-station in north London, Mr Pettigrew told invited guests: "These tunnels are a huge investment into London's future, in fact the most significant investment in the capital's electricity transmission system since the 1960s.

"For decades to come these tunnels will support London's growth and its ambition (to) transport power that millions of people rely on in their day to day lives as they work, live and travel in this great city."

The National Grid has recently flicked the switch to energise more than 124 miles of high voltage electricity cables that carry 20% of the capital's electricity demand - but for Charles's 'underground tour the power was turned off for safety.

The tunnels, running from Hackney in the east to Willesden in the west, and from Kensal Green to Wimbledon in the south also house some of the local electricity network company's cables, saving money and disruption.

The heir to the throne and his wife also met staff, stakeholders and local community members during the event.

Charles and Camilla chatted to school children who have visited the National Grid's education centre, set up to encourage young people to learn more about STEM (science, technology, engineering and mathematics) subjects.

To launch the project the couple both pressed a button as the song I've Got The Power by Snap blared out from speakers. They then inspected a plaque that commemorated the event.

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