BP has "temporarily" stopped the flow of oil pouring into the Gulf of Mexico, it announced tonight, 88 days after an explosion on the Deepwater Horizon drilling rig started oil spewing out from the Macondo well.The firm said the shutdown was part of an "integrity test" to see if the leaking wellhead can finally be contained. "It's a great sight but it's far from the finish line," Doug Suttles, a senior BP executive, told reporters, adding it was only a temporary shutdown while the integrity test, scheduled to take up to 48 hours, was concluded. Pressure readings are to be taken every 12 minutes. These will determine whether the flow will have to be restarted to avoid causing further damage to the well.In the event that the cap cannot contain the leak completely, BP hopes it will still mean the majority of leaking oil can be captured and put onto storage ships.President Barack Obama called the end of the flow of oil into the ocean a "positive sign," but cautioned that the latest effort was still in the testing phase. BP is preparing a "kill" operation that aims to seal off the well permanently by 13 August."I have a high degree of confidence we can substantially decrease the oil coming into the environment," Admiral Thad Allen, the federal incident commander, said, before today's operation was launched.Earlier in the day, US politicians passed a bill that could effectively ban BP from any new drilling in US waters for seven years.A House committee agreed measures to stop any company that's caused 10 deaths or more during operations from obtaining offshore oil exploration permits.BP is not named specifically, but would certainly be hit should the draft legislation pass into law. Eleven men were killed when its Deepwater Horizon rig exploded and sank in April.Any explorer responsible for deaths during drilling, production facilities, or refineries, and guilty of breaking US health and environment laws would also be censured.The oil spill in the Gulf of Mexico has turned into America's worst environmental disaster and caused a tide of hatred against BP in the US.Before coming into effect, the proposal must be passed by both houses of Congress.