estimate of the amount of heavy metals and other chemicals on board, they also claimed there were more than 5,500 tonnes of oil on the Spar – while Shell's estimate was 50 tonnes. For context, the Exxon Valdez oil spill involved around 42,000 tonnes. Greenpeace mounted an energetic media campaign that influenced public opinion against Shell's preferred option. It disputed Shell's estimates of the contaminants on the Brent Spar, saying that these were much more than initially estimated. On 9 May, the German government issued a formal objection to the British government, with respect to the dumping plan. On 23 May, after several attempts, Shell obtained legal permission to evict the Greenpeace protesters from the Brent Spar, and they were eventually taken by helicopter to Aberdeen, Scotland, where they held a press conference. Towing of the platform to its final position began on 11 June. By this time, the call for a boycott of Shell products was being heeded across much of continental northern Europe, damaging Shell's profitability as well as brand image. German Chancellor Helmut Kohl protested to the British Prime Minister, John Major at a G7 conference in Halifax, Nova Scotia. Support from within the oil industry was not unanimous. Although oil production companies supported Shell's position, influential companies in the offshore construction sector stood to make money from onshore dismantling if a precedent could be set, and consequently supported the Greenpeace point of view. On 20 June, Shell had decided that their position was no longer tenable, and withdrew their plan to sink the Brent Spar. They released the following statement: "Shell's position as a major European enterprise has become untenable. The Spar had gained a symbolic significance out of all proportion to its environmental effect. In consequence, Shell companies were faced with increasingly intense public criticism, mostly in Continental northern Europe. Many politicians and ministers were openly hostile and several called for consumer boycotts. There was violence against Shell service stations, accompanied by threats to Shell staff." In early July, the Norwegian government gave Shell permission to mothball the Brent Spar in Erfjord. It remained there for several years while other options for disposal were considered. Aftermath Having moored the Brent Spar in Erfjord, Shell commissioned the independent Norwegian consultancy Det Norske Veritas (DNV) to conduct an audit of Spar's contents and investigate Greenpeace's allegations. Greenpeace admitted that its claims that the Spar contained 5500 tonnes