Nigeria's National Oil Spill Detection and Response Agency recommended the fine to the country's MPs this week. The fine would be the largest Shell has ever received in Nigeria and amount to about $125,000 for each barrel of oil split in the Bonga field. By contrast, BP is facing a maximum fine of $4,300 per barrel in the US following the Gulf of Mexico. Shell reacted angrily to the recommendation. "We do not believe there is any basis in law for such a fine," the company said. Neither do we believe that Shell has committed any infraction of Nigerian law to warrant such a fine. The Anglo-Dutch company estimated that about 40,000 barrels were spilt at Bonga, making it Nigeria's worst offshore spill in more than a decade. However, Shell disputes claims that any of the oil reached the shore and says that its response to the spill was rapid. The fine will need approval by Nigeria's parliament. The prospect of Nigeria trying to impose the fine is troubling for Shell, which has been producing oil in the west African country since the 1950s. Shell's fight in Nigeria came as Argentina stepped up its legal battle against UK companies trying to develop oil reserves off the Falkland Islands. The Argentine government said it is preparing to launch legal action against Premier Oil, which last week signed a $1bn deal last week to develop Rockhopper Exploration's Sea Lion field and intends to have first oil flowing by 2017. Argentina said it had written to Premier Oil to warn it against the "illegal" activities in the islands it calls Las Malvinas.