In Minnesota, Xcel Energy, formerly known as NSP, says customers can expect to pay as much as 50 percent more for natural gas heat this winter. Last month, the company was projecting a 20 percent rise in winter heating bills, but a surge in natural gas prices forced Xcel to revise its forecast. Scott Holtz, a gas supply manager for Xcel Energy, says the world's oil producers are responsible for the rate increase. Both Senator Paul Wellstone and Senator Rod Grams are asking the President to set aside 500 million dollars to help low income families pay for heat this winter. But they don't agree on who's to blame for the sharp increase.