Magic Circle law firm Allen & Overy has been hit with a £12m claim from its former clients for alleged negligence on its work on the leasing of the London stadium to West Ham United Football Club.

Allen & Overy’s poor work on the 2013 the concession agreement — which governs the club's 99-year lease of the ground — risks a loss of £6,926 for every West Ham home game, according to the claim from the stadium’s owners E20 Stadium and London Legacy Development Corporation (LLDC).