Londoners got a shock today as F1 superstar Lewis Hamilton was spotted behind the wheel of a black cab.  

New world champion Lewis Hamilton swapped his single-seat F1 car for a black cab as he drove through the capital this morning with Finnish star Mika Hakkinen.

The 23-year-old star was promoting an anti-drink drive campaign and encouraging designated drivers.

Hamilton and Hakkinen hailed the public transport drivers who get people home safely as ‘the real champions’ behind the wheel.

Hamilton said: "Our message is simple: never drink and drive. If you are out celebrating, use a designated driver, whether that is a taxi, bus, tube or train driver or a friend who doesn't drink that evening.

"Ever since I passed my driving test, whenever I go out with my friends I'm always happy to be the designated driver. That way I know everyone gets home safely."

Hakkinen added: "Lewis and I want to use our profiles positively and try to change attitudes.

"It's great we've been able to come to London and highlight the real champions, the people who get us home safely every day of the week."

The champions drove black cabs across London's Tower Bridge towards City Hall to join forces with professional drivers from Transport for London.

Last year, 460 people were killed and approximately 1,750 seriously injured in the UK as a result of drinking.

Hamilton and Hakkinen were joined at the Johnnie Walker-organised event by London Mayor Boris Johnson, who has also experienced some track time recently after appearing as the Star in a Reasonable Priced Car on Top Gear.

Boris Johnson said: "Too many lives are tragically wasted through drink-driving accidents, so I hope that the message really gets through by having Lewis and Mika, two of the world's most talented and renowned car drivers, leading the call for people to think before getting into a car."

Lewis Hamilton became the youngest ever F1 champion last month after a nail-biting finale in Brazil, winning the championship by one point from Ferrari’s Felipe Massa.

This weekend sees the BBC Sports Personality named with Hamilton hotly tipped for victory after losing out to Joe Calzaghe last year.

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