Democratic White House hopeful Barack Obama charged that oil giants were betting their record profits on John McCain and accused his Republican foes of "lying" about his own energy plan.
Senator Obama and fellow Democrats on Tuesday painted McCain as a puppet of "Big Oil," seeking to leverage public anger over high gasoline prices and bind him to the economic legacy of President George W Bush.
"Under Senator McCain's plan, the oil companies get billions more, we don't pay any less at the pump, and we stay in the same cycle of dependence on oil that got us into this crisis," Obama said in Ohio.
"The oil companies have placed their bet on Senator McCain, and if he wins, they will continue to cash in while our families and our economy suffer and our future is put in jeopardy."
Obama chose to press home his attack in the heart of Ohio, a midwestern state hammered by the loss of heavy industry jobs which is a perennial bellwether in US presidential elections.
The Illinois senator argued that though McCain was right to argue America had grown addicted to foreign oil over the past 30 years, he was a part of the problem, as he served in Congress for most of that time.
And Obama fought back after being ridiculed by McCain for urging drivers to properly inflate their tires, which even the US government says could reduce national oil consumption by at least three percent a year.
"They know they're lying about what my energy plan is," he said after Republican aides mockingly handed out tire gauges to reporters to sum up Obama's policies.