lord Mayor said ' dangerously addictive ' machines prey on vulnerable . He also warned retailers to tackle ' clustering ' of betting machines in areas . Campaigners blame ' cluster betting ' terminals for a rise in problem gambling . Gamblers can earn £ 100 per spin in 33,000 betting shops across the uk .
London Mayor said 'dangerously addictive ' machines prey on vulnerable . He also warned ministers to tackle 'clustering ' of betting shops in areas . Campaigners blame 'fixed odds ' terminals for a rise in problem gambling . Gamblers can stake £100 per spin in 33,000 betting shops across the UK .