Terry Smith, one of the most outspoken senior figures in the City of London, said today he could "quite clearly track" how the defections of individual brokers to an arch-rival directly impacted first half performance and helped drag revenues down 8% compared with last year.

Speaking to Financial News about the results this morning, Smith said "The broker defections after the raid by BGC had an effect. We can track that quite clearly - the individual brokers came out of certain desks and the revenue from those desks dropped as a result."