The conference, which convened the heads of comms from some of the largest global brands, including Coca-Cola, British American Tobacco, PepsiCo and Nokia, took the issue of the globalisation of PR as its theme.

In a keynote speech, the Body Shop founder warned the audience that 'vigilante consumers' – who refuse to buy products from firms they do not trust – were becoming commonplace.

'Consumers rightly want to know the bigger story,' she said. 'If business communications has no moral sympathy, then God help us all.'

While deriding many PR approaches to the promotion of human rights, she praised some recent achievements. 'Nike has done a great PR job recently in opening its factories to journalists and hitting issues about its labour head-on,' she said. 'One action of disclosure has stopped 90 per cent of the anti-Nike news reaction.'

Roddick claimed real PR and marketing was about 'talking more sensibly and persuasively with customers', and decried unauthentic CSR as 'chequebook charity'.

She added: 'Anything that comes from the heart is unstoppable, and this is the sort of language PR professionals need to learn. Say you want to maximise profits, but not at the expense of social justice.'