The Sun, Britain's biggest selling newspaper, arranged a stunt bus to drive by the London hospital where the Duchess of Cambridge is due to give birth any day now.

The double-decker red bus took around a dozen royal enthusiasts on a short journey passing in front of the Lindo Wing at St Mary's Hospital.

But the large vehicle blocked the road, meaning an ambulance had difficulty getting through.

Photographers had to move traffic bollards to allow the on-call ambulance past.

The fans on board the stunt bus have been camped outside the hospital since 16 April waiting for the Duchess to be admitted.

Dressed in Union Jack flag suits they waved flags on the top deck of the bus to the sound of Land of Hope and Glory blaring.