The Guardian is to slash its costs by GBP54 million over the next three years and could start charging for some of its content after burning through GBP80 million of cash in only a year. David Pemsel, the chief executive of Guardian News & Media, told staff that he had no option but to cut operating costs by a fifth after revealing that the media group’s cash pile had fallen from GBP838.3 million to GBP735 million in the year to March 31.