Shanghai's many proud pyjama-wearers feeling the heat ahead of World Expo

If it's well into the day and you're seeing droves of pyjama-clad people, young and old, running errands in alleyways, taking shelter from the summer heat or roaming supermarket aisles in search of bargains, you must be in Shanghai.

People wearing pyjamas in public has been a hallmark of Shanghai street culture for decades.

Now it's a focal point for heated public debate after a controversial government-backed public etiquette clampdown targeting the practice ahead of this year's World Expo.

The crackdown on pyjama-wearing in public has reminded many of a similar crackdown in Beijing - on the capital's hordes of topless males - ahead of the summer Olympics in 2008.

The Qiba neighbourhood in Shanghai's New Pudong district, only three bus stops from the World Expo site, has mobilised neighbourhood committee officials and volunteers since July to talk people out of the habit of wearing pyjamas in public.

The initiative has split public opinion. Some see pyjama-wearing in public as an embarrassment, while others view it as a tradition and a right.

China News Weekly quoted Qiba Neighbourhood Committee director Shen Guofang as saying it had started the campaign because it was worried that the sight of people parading about in their pyjamas could leave a bad impression among foreign visitors.