US President Barack Obama has called on his party and supporters to back clean energy campaign. Visiting areas affected by the BP oil spill, he said the full resources of government were being deployed, with 17,500 National Guard troops available. Mr Obama is touring Mississippi, Alabama and Florida, on his fourth visit to the region since the spill. Tens of thousands of barrels of oil a day have gushed into the Gulf of Mexico since a rig exploded and sank in April. Mr Obama promised Americans living on the Gulf of Mexico that their beaches would be restored to pristine condition, vowing that he would bring full force to bear on BP to pay for the damage from oil pollution. He is due to put his demands to BP executives when he meets them face to face for the first time tomorrow.<br/>