It will be the largest group litigation in English civil court history, according to law firm Pogust Goodhead, which is leading the case on their behalf.Following several years of preliminary court hearings, judge Finola O'Farrell ruled in a judgement published Wednesday that the case must go to trial."It is now time to avoid further delay and make substantive progress in determining the dispute," she said in a 17-page judgement dealing with various aspects of the complex litigation."Having committed ecocide through their negligent conduct prior to the collapse of the dam in November 2015, BHP continues to destroy shareholder value in the way it conducts this litigation," the law firm's CEO Tom Goodhead said in a statement.A spokesman for the London-listed BHP said the multinational "denies the claims in their entirety" and will continue to defend itself against the claim."