In one incident, a group of female workers were forced to stand in the blazing sun for two hours as punishment for failing to make hundreds of pairs of shoes quickly enough.

One worker, 23, said: 'They throw shoes and other things at us. They growl and slap us when they get angry. It's part of our daily bread.'

Greg Muttitt, campaigns and policy director at anti-poverty charity War on Want, said: 'Sportswear brands such as Nike have a clear responsibility to ensure ethical standards from their suppliers. Yet, time and again, companies have failed to achieve it.'

Nike, which is promoted by sports stars such as Rafael Nadal, Tiger Woods and Wayne Rooney, sells the trainers for up to £50 a pair.

Yet, a report by by the company revealed that workers at the two factories were subjected to 'serious and egregious' physical and verbal abuse. It also found that almost two-thirds of its 168 factories making Converse products across the world failed to meet company standards.