European brokers have added their voices to fears over the growing influence of high frequency trading firms, less than a week after a US senator urged the Securities and Exchange Commission to ban one of their most lucrative trading strategies.

High frequency traders, which include hedge funds and proprietary trading houses such as Optiver and Getco, are a growing force in Europe's equity markets, where they use state-of-the-art computers to spot patterns and profit from tiny price movements.