WASHINGTON: The U.S. House has approved a measure that would ease a longstanding ban on offshore oil drilling and try to spur greater use of alternative fuels as Democrats and Republicans engaged in a bitter pre-election clash over the nation's energy future. Under the Democratic legislation, adopted Tuesday night by a vote of 236-189, oil companies would lose some tax benefits, utilities would be required to produce 15 percent of their electricity from renewable sources by 2020 and a ban on developing fuel from Rocky Mountain shale would be lifted. The legislation, which faces significant hurdles to becoming law before Congress breaks at the end of the month, would allow drilling as close as 50 miles, or 80 kilometers, from the coastline if adjacent states agree and 100 miles out no matter a state's position. It would impose stricter oversight on the agency that handles oil leasing and royalty payments after recent disclosures of improper relationships between its employees and oil industry representatives. "We are opening up to 400 million acres off the Atlantic and Pacific coasts to drilling and expanding the availability of oil by at least two billion barrels," said Representative Nick Rahall, the West Virginia Democrat who leads the Natural Resources Committee. "And we have done so in a balanced, reasonable and responsible manner." Republicans, who have made political gains by portraying Democrats as flatly opposed to new drilling, said the measure was a sham intended to provide Democrats cover from voters furious over gas prices. They faulted it for failing to add incentives for coal and nuclear power and for not limiting environmental suits against drilling proposals. A Republican effort to sidetrack the measure with a procedural tactic was rebuffed on a vote that generally adhered to party lines. That cleared the way for approval of the proposal, which drew strong support from Democrats, including conservatives from states with strong oil and gas industries. "It represents a critical turning point," said Representative Dan Boren, Democrat of Oklahoma, who praised the bill for provisions that would encourage greater use of natural gas. Though Republicans derided the measure, saying it kept too much of the Outer Continental Shelf and the underlying reserves off limits to drilling, the decision to entertain expanded offshore drilling was a stark reversal for Democrats, who have supported a coastal drilling ban since 1982. They were motivated by the Republican attacks and by the view that keeping the stricter ban would be unrealistic this year. Relaxing the ban became the party's fall-back position. Democrats said Republicans were frustrated because the bill robbed them of a chief line of attack in allowing Democrats to vote for new drilling in conjunction with clean energy initiatives. But Republicans called the entire exercise political, saying Democrats were willing to consider new offshore drilling only because they were certain the bill would not become law. The outlook for the measure is uncertain, with only two weeks before Congress is set to break until at least the November elections and perhaps until next year. The Senate is preparing to take up a similar bill, but even if it averts a filibuster, it seems unlikely that the bills could be reconciled before the break. And the White House has threatened a veto of the House plan.