James Corden performs 'Mary Poppins' live on a London street crossing

Supercalifragilisticexpialidocious!

That's what everyone is calling James Corden's brilliant performance of Mary Poppins that he took off the stage - and onto the London streets.

With legendary actor Sir Ben Kingsley cast in the role as Bert (originally played by Dick Van Dyke), he and James captured the audience of drivers - who didn't really have a choice but to watch them as they waited at their stop signs.

Watch the full performance above!