Britain's most prominent adman yesterday accused two former business associates of spearheading a "bitterly hostile" campaign against him and his Italian chief operating officer as one of the most colourful libel trials for years got under way at London's High Court.

Lawyers for Sir Martin Sorrell, founder of the WPP marketing services empire, claimed a libellous internet blog had been set up and privacy-infringing e-mails, with a "vicious jpeg image" attached, had been disseminated to discredit him and Daniela Weber.