Guardian: BP is facing a bill of up to $34bn from the Gulf of Mexico disaster after US senators demanded the oil company deposited $20bn into a ring-fenced account to meet escalating compensation costs. The sum dwarfs many analysts’ previous estimates, shared by BP, that put the cost of the clean-up effort and payment of damages to affected communities, such as fishermen, closer to a total of $5bn. Shares in BP nose-dived by more than 9% today as investors took fright at the demand by …