BP's attempts to flood the leaking oil pipe with mud have failed to halt the spill Photo: AP  BP chief executive Tony Hayward talks to Jose Rivera, of Honduras, in a mess hall for cleanup workers, in Venice, Louisiana Photo: AP  BPchief executive Tony Hayward stands aboard the Discover Enterprise drill ship during recovery operations at the Deepwater Horizon oil spill site Photo: AP  Oil floats on the surface of the water in Pass A Loutre near Venice, Louisiana Photo: Reuters  Television satellite trucks occupy a closed beach on Grand Isle, Louisiana Photo: Getty Images  US President Barack Obama on the Louisiana coastline while touring damage caused by oil spill Photo: Reuters  Meanwhile Eric Holder, the US Attorney General, will visit the site of the spill for the first time on Tuesday. He will meet with federal prosecutors and state attorneys general in a move that will increase speculation that a criminal investigation will be launched. The development could hit BP’s share price.  More than five techniques have now failed to halt the flow, and on Monday BP was preparing to send robots down to cut a pipe near the source of the leak. This will allow a box to be lowered over the well and oil to be pumped to the surface, but officials warned that it could also make the situation worse.  "Clearly we do have an oil-spill response plan in place, it was an integral part of our permitting with the MMS [the regulator] and it was specifically agreed with and approved by the MMS," the company said. "It sets out the actions, considerations, plans and steps that will be used in the case of an oil spill, and it is this plan that has been in action in response."  US politicians investigating the leak for the Energy and Commerce Committee have now released documents showing that BP staff raised concerns about pressure on board the rig in November and March. Witnesses have also given testimony about arguments over safety procedures before the Deepwater Horizon rig, operated by contractor Transocean, exploded last month, killing 11 men.  The company will be braced for a further fall in its share price, as it admitted over the weekend that the spill may not be halted until August. Last night, US forecasters predicted that winds could spread the slick from Louisiana across to the Alabama and Mississippi coastlines.  BP fell 5pc to 494.8p in London on Friday and has lost a quarter – or £30bn – of its market value since the blast on April 20.
BP was given permission to drill in the Gulf of Mexico after submitting    documents promising it was equipped to deal with a spill 10 times larger    than the current leak.