The US Department of Justice (DoJ) has given the starkest indication yet that it is looking for the maximum punishment for BP's part in the 2010 Deepwater Horizon disaster.
In documents filed with the New Orleans court hearing the civil case, the oil giant was accused of "gross negligence and wilful misconduct" and of fostering a "culture of corporate recklessness" in advance of the Gulf of Mexico oil spill.
The DoJ said internal emails showed that "the behaviour, words and actions of these BP executives would not be tolerated in a middling-size company manufacturing dry goods for sale in a suburban mall".
BP denies gross negligence and said it "looks forward to presenting evidence on this issue".
The trial in New Orleans is set for 14 January.
The toughness of the DoJ's statement disappointed markets and according to a note issued by Oriel Securities,"hope of an out-of-court settlement is fading".