The Notting Hill Carnival is Europe's biggest street festival, attracting 1.5 million people over each August bank holiday to the streets of west London. Financially, it nets the capital GBP93 million (HK$1.3 billion).
Yet, it's never far from controversy, and this year is no different, The organisers claim that London's mayor, Ken Livingstone, is sabotaging the event. That's odd, because he is usually seen as a supporter of black Caribbean rights in the capital.
Mr Livingstone is championing a rival mini-carnival, called Caribbean Showcase, which is planned for Hyde Park on carnival's biggest day - today. Why he's doing this is not clear. Critics, unsurprisingly, blame the mayor's 'growing ego'.
The Notting Hill Carnival was set up 41 years ago as an antidote to the troubled race relations in the former slum area. The neighbourhood used to be grotty and crime-ridden, home to new black immigrants and resentful white locals. That combustible mix ignited seemingly every year, around this time.
That's no longer true. Today's trendy Notting Hill and its surrounding environs are the model of London's envied racial integration, helped no end over the decades by the annual carnival.
So why change things? The answer may begin a few years ago, when a local government committee advised that the carnival had outgrown the area. It said 1.5 million people parading on floats - through crowds so densely packed that it's impossible to move through the narrow streets - had become a huge safety risk.